chore(java): install maven 3.8.1 at runtime (#651)

This PR was generated using Autosynth. 🌈

Synth log will be available here:
https://source.cloud.google.com/results/invocations/e94472c3-adac-4a62-b2e3-9e3d53a2f9cd/targets

- [ ] To automatically regenerate this PR, check this box. (May take up to 24 hours.)

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

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-dlp.git",
-        "sha": "9e2966ee46dff2cd7d168aff0383cb0fc3db2416"
+        "sha": "585a07692107ef1478c44f028b1c08c345162fcd"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "9a238a0623879c3de129a376c6085d4a862f6eb9"
+        "sha": "ad7fd76e17bf9494a3e47ff9cf445f61564432e0"
       }
     }
   ],