Update the IDEA plugin to use google-java-format 1.8.

PiperOrigin-RevId: 318495968

Author: java-team-github-bot

idea_plugin/build.gradle

@@ -15,15 +15,15 @@
  */
 
 plugins {
-  id "org.jetbrains.intellij" version "0.4.18"
+  id "org.jetbrains.intellij" version "0.4.21"
 }
 
 repositories {
   mavenCentral()
 }
 
 ext {
-  googleJavaFormatVersion = '1.7'
+  googleJavaFormatVersion = '1.8'
 }
 
 apply plugin: 'org.jetbrains.intellij'
@@ -37,7 +37,7 @@ intellij {
 patchPluginXml {
   pluginDescription = "Formats source code using the google-java-format tool. This version of " +
                       "the plugin uses version ${googleJavaFormatVersion} of the tool."
-  version = "${googleJavaFormatVersion}.0.5"
+  version = "${googleJavaFormatVersion}.0.0"
   sinceBuild = '201'
   untilBuild = ''
 }

idea_plugin/resources/META-INF/plugin.xml

@@ -12,6 +12,8 @@
 
   <change-notes><![CDATA[
     <dl>
+      <dt>1.8.0.0</dt>
+      <dd>Updated to use google-java-format 1.8.<dd>
       <dt>1.7.0.5</dt>
       <dd>Added a version for 2020.1+ IDEs.</dd>
       <dt>1.7.0.4</dt>