The short answer is yes, Android development is production ready for UE4, but to respond to the points Dredok raised:
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better support for higher range of devices: Here is a link to the Android devices currently supported (with more supported every build):
https://wiki.unrealengine.com/Android_Device_Compatibility -
better rendering capabilities (and performance in general) for older devices: Development will be focused on newer devices
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support a movie or splashscreen at the start: This is currently supported.
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reduce the APK size for small games: This is something the developer currently needs to control at the packaging phase, but efforts are being made for this process to be more automated.
So while UE4 is production ready for Android development, improvements are still being made.