Add an install flag to force non-staged APEX update

This is a development only feature to speed up development workflow for
teams that have their code package in an APEX.

Bug: 290750901
Test: m
Test: atest ApexManagerTest
Test: see other change in the topic
Merged-In: Ic0abb9e97d529910805af50208baf42b9b28b171
Change-Id: Ib452dcdbdd30991f60205f94be25389379153183