Fix ApkLite attribute parsing

Reads properly namespaced attributes only, and always assigns
regardless of presence to ensure that last tag is taken, mirroring
full parsing.

Also fixes targetSdkVersion parsing so that it mirrors the logic used
by the full parser.

Bug: 184942889

Merged-In: I6c7014e5dae0f6f15268f0271c133879a89f5bc7
Change-Id: I6c7014e5dae0f6f15268f0271c133879a89f5bc7