Revert "Set targetsdkversion to future level if TARGET_BUILD_APPS is not empty"

This reverts commit e33e25b4.

Reason for revert: may causing b/209301265,
Test: https://android-build.googleplex.com/builds/abtd/run/L66400000952203490
Change-Id: Ifcccdcfbfc014d4172f4d9488ea699380d3f3ebe