Commit b4f17069 ("sepolicy:  Drop
BOARD_SEPOLICY_IGNORE/REPLACE support.", Mar 2015) made it a compile
time failure to use BOARD_SEPOLICY_REPLACE or BOARD_SEPOLICY_IGNORE.
As these restrictions have been in place since 2015, we can safely
assume all usages of this have been cleaned up, and there is no further
need to check for this.

8 lines deleted from Android.mk, 1720 lines to go.

Test: compiles.
Change-Id: I23249e4b2e9ec83cb6356a6c5a6e187ae1fc9744