This is now the default, and we will be removing non-GlobalThinLTO configuration.
Also changed handling for lto: never, it doesn't need to create an
lto-none variant.
Change-Id: I971baa920df867fb762923d925eed22215a89c27
Test: presubmit
lto has different behaviour depending on the GLOBAL_THINLTO env var
value.
Tests for GLOBAL_THINLTO=true will be added in a follow up CL.
Test: presubmit
Bug: 169004486
Change-Id: I45f6a35eb26bdb1beeb3ff5f2c0c0cdc8fd8c41f
This test confirms the behavior when LTO is disabled generally but
then enabled for a specific target.
Bug: 261733821
Test: Unit test
Change-Id: I415cd0146f2b83d85654239550d129f87e9001bc