SuspendSepolicyTests: Use target device grep

Some vendors reported issue running the test since thier host
environment was missing the path to grep command.

Use the target device grep instead.

Bug: 381369000
Test: atest SuspendSepolicyTests
Change-Id: Id891e9bcdfe00992b98124319e821d0bbb663282
Signed-off-by: Kalesh Singh <[email protected]>
(cherry picked from commit d3b68657fd3fe2d50238a01cd39073658f8cf031)
(cherry picked from commit 42f7e8dc09a4fc841cf7c7aabc875f22560cc8e5)
1 file changed