Timestamps in pyc files and zip archives were causing cache misses in RBE.
Bug: b/322788229
Test: Ran a few local builds and verified improved cache hit rate for metalava actions.
Change-Id: I9375694d26a107f5c0c43bbd685bd8e86349d187
This signifigantly improves the startup time of soong-built
python binaries. For example, running
`m apexer && time out/host/linux-x86/bin/apexer` gives
0.734s before this cl, and 0.094s after.
Fixes: 259718110
Test: Presubmits
Change-Id: Ib19e83e2c60c39a849525be117279c318de3afa7