Use raw {min,target}_sdk_version properties in android_app converter

The logic of EffectiveVersionString is product-variable dependent and
is being implemented bazel-side in order to produce product agnostic
BUILD files. A required additional product variable is added to the
export list, and the "updatable" property of android_app is also bp2build-converted.
Handling of max sdk version was not correct (it does not affect
manifest values in Soong), so removing it for now.

Bug: 274474008
Bug: 274474002
Test: CI
Change-Id: I7a10bfabf914c8e86064b7ce61926701f87517e3