GitHub Actions - use gradle:jdk8 container to provide Java

.github/workflows/build.yml

@@ -15,7 +15,6 @@
 
 name: Build
 on: [push, pull_request]
-
 jobs:
 
   # Run Gradle Wrapper Validation Action to verify the wrapper's checksum
@@ -37,18 +36,13 @@ jobs:
     name: Test
     needs: gradleValidation
     runs-on: ubuntu-latest
+    container: gradle:jdk8
     steps:
 
       # Check out current repository
       - name: Fetch Sources
         uses: actions/checkout@v2
 
-      # Setup Java 1.8 environment for the next steps
-      - name: Setup Java
-        uses: actions/setup-java@v1
-        with:
-          java-version: 1.8
-
       # Cache Gradle dependencies
       - name: Setup Cache
         uses: actions/cache@v2
@@ -77,6 +71,7 @@ jobs:
     name: Build
     needs: test
     runs-on: ubuntu-latest
+    container: gradle:jdk8
     outputs:
       name: ${{ steps.properties.outputs.name }}
       version: ${{ steps.properties.outputs.version }}
@@ -88,12 +83,6 @@ jobs:
       - name: Fetch Sources
         uses: actions/checkout@v2
 
-      # Setup Java 1.8 environment for the next steps
-      - name: Setup Java
-        uses: actions/setup-java@v1
-        with:
-          java-version: 1.8
-
       # Cache Gradle dependencies
       - name: Setup Cache
         uses: actions/cache@v2

.github/workflows/release.yml

@@ -12,6 +12,7 @@ jobs:
   release:
     name: Publish Plugin
     runs-on: ubuntu-latest
+    container: gradle:jdk8
     if: github.repository != 'JetBrains/intellij-platform-plugin-template'
     steps:
 
@@ -21,12 +22,6 @@ jobs:
         with:
           ref: ${{ github.event.release.tag_name }}
 
-      # Setup Java 1.8 environment for the next steps
-      - name: Setup Java
-        uses: actions/setup-java@v1
-        with:
-          java-version: 1.8
-
       # Publish the plugin to the Marketplace
       - name: Publish Plugin
         env:
@@ -38,6 +33,7 @@ jobs:
     name: Update Changelog
     needs: release
     runs-on: ubuntu-latest
+    container: gradle:jdk8
     steps:
 
       # Check out current repository
@@ -46,12 +42,6 @@ jobs:
         with:
           ref: ${{ github.event.release.tag_name }}
 
-      # Setup Java 1.8 environment for the next steps
-      - name: Setup Java
-        uses: actions/setup-java@v1
-        with:
-          java-version: 1.8
-
       # Update Unreleased section with the current version
       - name: Patch Changelog
         run: ./gradlew patchChangelog