Polish "Use 2012 for copyright beginning year"

See gh-27734

buildSrc/src/main/java/org/springframework/boot/build/AsciidoctorConventions.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2021 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/DeployedPlugin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/autoconfigure/AutoConfigurationPlugin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2021 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/cli/AbstractPackageManagerDefinitionTask.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/constraints/DocumentConstrainedVersions.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/constraints/DocumentVersionProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/context/properties/ConfigurationProperty.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/mavenplugin/MavenPluginPlugin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2021 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/mavenplugin/PrepareMavenBinaries.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/processors/AnnotationProcessorPlugin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/starters/DocumentStarters.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/main/java/org/springframework/boot/build/starters/StarterPlugin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

buildSrc/src/test/java/org/springframework/boot/build/log4j2/ReproduciblePluginsDatActionTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/logger/DevToolsLogFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2019 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

spring-boot-tests/spring-boot-integration-tests/spring-boot-server-tests/src/intTest/java/org/springframework/boot/context/embedded/EmbeddedServletContainerTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2021 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.