Fix two syntax errors in .github/actions/set-up-bazel (#1058)

Fix two syntax errors in the action definition: the presence of `permissions:` at the top level, and the use of a non-string default value for action inputs.

Author: mhucka

.github/actions/set-up-bazel/action.yaml

@@ -23,16 +23,12 @@ inputs:
   debug:
     description: 'Run with debugging options'
     required: false
-    default: true
+    default: 'true'
   bazel-version:
     description: 'Version of Bazel to use:'
     required: false
     default: ''
 
-permissions:
-  actions: write
-  contents: read
-
 runs:
   using: 'composite'
   steps: