Sets github's test gradle usePreinstrumentedJars value to false by de…

…fault.

Some changes only occur when a new version of the jars are released. This will ensure all changes are tested when copied over.

This will allow integration_tests:sparsearray to run in Gradle before
a new version of preinstrumented jars are released.

Related to #7006

PiperOrigin-RevId: 428547156

.github/workflows/tests.yml

@@ -96,6 +96,7 @@ jobs:
           --no-watch-fs \
           -Drobolectric.enabledSdks=${{ matrix.api-versions }} \
           -Drobolectric.alwaysIncludeVariantMarkersInTestName=true \
+          -Drobolectric.usePreinstrumentedJars=false \
           -Dorg.gradle.workers.max=2
 
       - name: Upload Test Results