Rename variables to help make lines shorter (#877)

This should solve the yamllint line length complaints.

Author: mhucka

.github/workflows/ci-nightly-cirq-test.yaml

@@ -33,12 +33,12 @@ on:
         type: string
         default: "x64"
 
-      use_bazel_disk_cache:
+      use_disk_cache:
         description: Use Bazel disk_cache between runs
         type: boolean
         default: true
 
-      cache_bazel_tests:
+      use_test_cache:
         description: Allow Bazel to cache test results
         type: boolean
         default: true
@@ -99,20 +99,20 @@ jobs:
           # If we didn't get a cache hit on the installed Python environment,
           # something's changed, and we want to make sure to re-run all tests.
           if [[ "${{steps.python.outputs.cache-hit}}" == "true"
-                 && "${{github.event.inputs.cache_bazel_tests}}" != "false" ]]; then
-            echo "cache_bazel_tests=auto" >> "$GITHUB_ENV"
+                && "${{github.event.inputs.use_test_cache}}" != "false" ]]; then
+            echo "use_test_cache=auto" >> "$GITHUB_ENV"
           else
-            echo "cache_bazel_tests=no" >> "$GITHUB_ENV"
+            echo "use_test_cache=no" >> "$GITHUB_ENV"
           fi
           # Use the disk cache unless told not to.
-          if [[ "${{github.event.inputs.use_bazel_disk_cache}}" != "false" ]]; then
-            echo "use_bazel_disk_cache=true" >> "$GITHUB_ENV"
+          if [[ "${{github.event.inputs.use_disk_cache}}" != "false" ]]; then
+            echo "use_disk_cache=true" >> "$GITHUB_ENV"
           else
-            echo "use_bazel_disk_cache=false" >> "$GITHUB_ENV"
+            echo "use_disk_cache=false" >> "$GITHUB_ENV"
           fi
 
       - name: Set up Bazel with caching
-        if: env.use_bazel_disk_cache == 'true'
+        if: env.use_disk_cache == 'true'
         uses: bazel-contrib/setup-bazel@0.12.1
         env:
           USE_BAZEL_VERSION: ${{inputs.bazel_version || env.bazel_version}}
@@ -123,17 +123,17 @@ jobs:
           repository-cache: true
           bazelrc: |
             ${{env.bazelrc_additions}}
-            test --cache_test_results=${{env.cache_bazel_tests}}
+            test --cache_test_results=${{env.use_test_cache}}
 
       - name: Set up Bazel without caching
-        if: env.use_bazel_disk_cache == 'false'
+        if: env.use_disk_cache == 'false'
         uses: bazel-contrib/setup-bazel@0.12.1
         env:
           USE_BAZEL_VERSION: ${{inputs.bazel_version || env.bazel_version}}
         with:
           bazelrc: |
             ${{env.bazelrc_additions}}
-            test --cache_test_results=${{env.cache_bazel_tests}}
+            test --cache_test_results=${{env.use_test_cache}}
 
       - name: Configure TFQ
         run: |