chore: remove java 7 units check (#483)

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Source-Link: googleapis/synthtool@1a2878d

Author: yoshi-automation

.github/workflows/ci.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [7, 8, 11]
+        java: [8, 11]
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-java@v1

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-datastore.git",
-        "sha": "3aa2cf118342419a317a68f3ec1a61917bcbb511"
+        "sha": "c5f227b3ba517dedc79d0a2ab5a36a4306aa83c6"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "5d3c52f5db664eee9026db76b5bcb466f3a09ca9"
+        "sha": "1a2878d6909dd10ca4e3c1b5943d6622e996054e"
       }
     }
   ],