Sort and reorganize clear_vars.mk to make merges easier

Moved common variables from other sections back to the common section,
then sort each section.

Test: build-aosp_angler.ninja is identical before/after
Change-Id: Ibb75935205aa80aaa392c358f8d0599ba624f90d
Merged-In: Ibb75935205aa80aaa392c358f8d0599ba624f90d
(cherry picked from commit 3ea1a059175384793f2f2cf751fe550c568673d9)
1 file changed