[Android] make_apk: Refine the naming of AppInfo.

app_info.name => app_info.android_name,
android name will be used for Android project name, APK file name and Activity name.
app_info.original_name => app_info.app_name,
app_name will be used for the Android application name.
make it easier to read.
[Android] make_apk: generated android name by package.

The android name is generated from options.name now,
while the options.mame will be any string in future.
Generated from the last segment of package name is easier.
[Android] make_apk: Accepting any string to be application name.

The new w3c manifest spec requires accepting any string to be application name.
However in previous make_apk process, they were treated as invalid input.