Pin `setup-java` with a hash (#1122)

.github/workflows/beta.yml

@@ -23,8 +23,9 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
       - uses: actions/checkout@5f87f43226edfc1a08fc4c0d26875fa13e3540c4
-      - uses: actions/setup-java@v1
+      - uses: actions/setup-java@9519cf1382ac8dc61ad461f7f7cb45f033220189
         with:
+          distribution: 'zulu'
           java-version: '12.x'
       - uses: subosito/flutter-action@4389e6cbc6cb8a4b18c628ff96ff90be0e926aa8
         with:
@@ -36,8 +37,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-java@v1
+      - uses: actions/setup-java@9519cf1382ac8dc61ad461f7f7cb45f033220189
         with:
+          distribution: 'zulu'
           java-version: '12.x'
       - uses: subosito/flutter-action@4389e6cbc6cb8a4b18c628ff96ff90be0e926aa8
         with:
@@ -49,8 +51,9 @@ jobs:
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-java@v1
+      - uses: actions/setup-java@9519cf1382ac8dc61ad461f7f7cb45f033220189
         with:
+          distribution: 'zulu'
           java-version: '12.x'
       - uses: subosito/flutter-action@4389e6cbc6cb8a4b18c628ff96ff90be0e926aa8
         with: