Revert "chore(java11): compile with Java 11 (but using -source 8 -tar…

…get 8) (spinnaker#1108)" (spinnaker#1109)

This reverts commit e8eb098.

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-java@v1
         with:
-          java-version: 11
+          java-version: 8
       - name: Build
         env:
           BINTRAY_USER: ${{ secrets.BINTRAY_USER }}

.github/workflows/pr.yml

@@ -9,7 +9,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-java@v1
       with:
-        java-version: 11
+        java-version: 8
     - uses: actions/cache@v1
       with:
         path: ~/.gradle

.github/workflows/release.yml

@@ -14,7 +14,7 @@ jobs:
       - run: git fetch --prune --unshallow
       - uses: actions/setup-java@v1
         with:
-          java-version: 11
+          java-version: 8
       - name: Assemble release info
         id: release_info
         env:

Dockerfile.compile

@@ -1,4 +1,4 @@
-FROM openjdk:11
+FROM openjdk:8
 MAINTAINER [email protected]
 ENV GRADLE_USER_HOME /workspace/.gradle
 ENV GRADLE_OPTS -Xmx2048m