Update gradle usage and tests in GitHub Actions workflow

The 'gradle' usage in the GitHub Actions workflow file (main.yml) has been updated, transitioning commands from 'gradle' to './gradlew'. Along with this, 'gradle-build-action@v2' is now used for setting up Gradle. Test script execution name has been updated for clarity.

.github/workflows/main.yml

@@ -35,9 +35,11 @@ jobs:
           java-version: '${{ matrix.version }}'
           cache: 'gradle'
 
+      - name: Setup Gradle
+        uses: gradle/gradle-build-action@v2
+
       - name: Install Dependencies
-        run: gradle resolveDependencies
-        shell: bash
+        run: ./gradlew resolveDependencies
 
-      - name: test
-        run: gradle test -i
+      - name: Run tests
+        run: ./gradlew test -i