chore(java): install maven 3.8.1 at runtime (#679)

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Source-Link: googleapis/synthtool@ad7fd76

.github/workflows/ci.yaml

@@ -12,6 +12,9 @@ jobs:
         java: [8, 11]
     steps:
     - uses: actions/checkout@v2
+    - uses: stCarolas/setup-maven@v4
+      with:
+        maven-version: 3.8.1
     - uses: actions/setup-java@v1
       with:
         java-version: ${{matrix.java}}
@@ -37,6 +40,9 @@ jobs:
         java: [8, 11]
     steps:
     - uses: actions/checkout@v2
+    - uses: stCarolas/setup-maven@v4
+      with:
+        maven-version: 3.8.1
     - uses: actions/setup-java@v1
       with:
         java-version: ${{matrix.java}}
@@ -46,6 +52,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+    - uses: stCarolas/setup-maven@v4
+      with:
+        maven-version: 3.8.1
     - uses: actions/setup-java@v1
       with:
         java-version: 8
@@ -57,10 +66,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+    - uses: stCarolas/setup-maven@v4
+      with:
+        maven-version: 3.8.1
     - uses: actions/setup-java@v1
       with:
         java-version: 8
     - run: java -version
     - run: .kokoro/build.sh
       env:
-        JOB_TYPE: clirr
+        JOB_TYPE: clirr

synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-storage-nio.git",
-        "sha": "22b3c460d9ae90174860cb479bc6d16b8c3ed891"
+        "sha": "fc3253d8ac0826626dad271f1d318ffd68724de0"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "9a238a0623879c3de129a376c6085d4a862f6eb9"
+        "sha": "ad7fd76e17bf9494a3e47ff9cf445f61564432e0"
       }
     }
   ],