Stop setting Mainline build environment variables
Toggling build environment variables for the Mainline module test invocations increases build times since Soong has to reconfigure itself.
This change updates Atest to no longer modify environment variables before building and leaves it up to the user to properly set up their environment for Mainline testing using `banchan`. Building a module on the command-line using `m` will also no longer trigger a rebuild in Atest since the user's environment variables are inherited.
Note that we also no longer need to workaround capex files that can't be installed. This is because `banchan` ensures that Mainline builds generate apex files.
# Testing notes
This change was testing by running the below commands:
1. `banchan com.google.android.os.statsd mainline_modules_x86_64`
2. `time m com.google.android.os.statsd`
3. `time atest-dev FrameworkStatsdTest[com.google.android.os.statsd.apex] -b`
The timestamp of the `statsd` apex was inspected between steps 2 and 3. The below summarizes the state before and after the changes.
## Before
Step (2) took 20 min and step (3) took 32 min. The apex timestamp changes between builds.
## After
Step (2) still takes ~20 min and step (3) now only takes 4 min (-87.5%). The apex timestamp does not change implying that it was not rebuilt.
Bug: 259496712
Test: make clobber && time m atest && time atest-dev CtsNetTestCasesLatestSdk[CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex] --verbose
Test: m mts-conscrypt
Change-Id: Ib7c927e8f4d070a85ea1b5beccd0977c2488e413
2 files changed
