Allow ExtServices to use tflite_support

tflite_support provides some tflite ops and utils functions.

> How big is the binary size increase for affected APEXes?
+100K
> Is the new dependency committed to support previous platform releases?
note that you have to support all the releases starting from the minSdkVersion value you are declaring
Yes.
> Is the new dependency being developed AOSP-first or internal?
AOSP-first. We don't "develop" it there tho.
We import the code from github and the library is developed by another
team in google.
> What’s the testing strategy for the new dependency? Does it have its own tests, and are you adding integration tests?
We test the library with our own unit and integration tests.

Bug: 169147920

Test: build/soong/scripts/update-apex-allowed-deps.sh

Change-Id: Ic15226dd36dce98f9a3e54672353f87adcc6312f