Add androidTargetSdkVersion as an option to update the Android SDK (#298)

* Add androidTargetSdkVersion as an option to update the Android SDK API level

* Fix build script

* Update default value

* Add JAVA_HOME

* Use Unity_path

* Update src/model/android-versioning.test.ts

Co-authored-by: Webber Takken <webber@takken.io>

* Correct JAVA_HOME

* Use unity_path

* Update JAVA_HOME to use path found from 2020.3

* Dynamically determine JAVA_HOME

* Update path determination

Co-authored-by: Webber Takken <webber@takken.io>

src/model/android-versioning.test.ts

@@ -28,4 +28,14 @@ describe('Android Versioning', () => {
       expect(AndroidVersioning.determineVersionCode('1.2.3', 2)).toBe(2);
     });
   });
+
+  describe('determineSdkManagerParameters', () => {
+    it('defaults to blank', () => {
+      expect(AndroidVersioning.determineSdkManagerParameters('AndroidApiLevelAuto')).toBe('');
+    });
+
+    it('uses the specified api level', () => {
+      expect(AndroidVersioning.determineSdkManagerParameters('AndroidApiLevel30')).toBe('platforms;android-30');
+    });
+  });
 });