[Android] Add xwalk_app_template_apk to xwalk_app_template's dependency

xwalk_app_template_apk is to verify the correctness of xwalk_app_template
before creating the package of it.
Set the dependency although, xwalk_app_template doesn't rely on
xwalk_app_template_apk to build.
Merge pull request #2386 from wang16/template_apk

[Android] Add xwalk_app_template_apk to xwalk_app_template's dependency