Update api-level values to string format

Changed api-level values to be string literals.

Author: yschimke

.github/workflows/main.yml

@@ -40,15 +40,15 @@ jobs:
             target: google_apis
             arch: x86_64
           - os: ubuntu-latest
-            api-level: 37.0
+            api-level: "37.0"
             target: google_apis_playstore_ps16k
             arch: x86_64
           - os: ubuntu-latest
-            api-level: 37.0
+            api-level: "37.0"
             target: google_apis_ps16k
             arch: x86_64
           - os: ubuntu-latest
-            api-level: 37.0
+            api-level: "37.0"
             target: playstore_ps16k
             arch: x86_64
           - os: ubuntu-latest