Skip system/bin/bootstrap/linkerconfig

Early processes can't rely on APEXes anyway. We don't need to run
linkerconfig.

This helps to reduce the storage usage (no
/system/bin/bootstrap/linkerconfig) and the boottime (not running
linkerconfig).

If we need more complicated linker config even for early processes, then
we could generate it at build-time and use it like recovery version.

Bug: 262330207
Bug: 260982509
Test: MicrodroidAppTest
Test: device boots
Change-Id: Iceca5ffdb1655fd94e90b0091f439bd22130185e