[Android] Simplify check for --app-{local-path,root,url} in make_apk.

The existing check for those parameters is very convoluted and hard to
follow.

Split it into several smaller checks with different error messages for
each of them.
Merge pull request #2171 from rakuco/separate-checks-for-app-parameters-make_apk

[Android] Simplify check for --app-{local-path,root,url} in make_apk.