Increase Android CI heap size to 6GB (#229)

Increase Android CI Gradle heap size from 4GB to 6GB

This addresses Java heap space errors in CI by increasing the maximum heap size available to Gradle during Android test runs.

Author: JesseNoseworthy

.github/workflows/ci.yml

@@ -87,7 +87,7 @@ jobs:
 
       - name: Run Android tests
         env:
-          GRADLE_OPTS: -Xmx4g
+          GRADLE_OPTS: -Xmx6g
         run: |
           echo "STOREFRONT_DOMAIN=\"myshopify.com\"" > sample/.env
           yarn module build