Re-enable MTE stack on fullmte builds.

The new toolchain has been rolled, and so we can re-enable stack MTE
instrumentation.

Bug: 320448268
Bug: 292478827
Test: atest bionic-unit-tests bionic-unit-tests-static \
      CtsTaggingHostTestCases debuggerd_test CtsGwpAsanTestCases \
      gwp_asan_unittest CtsHostsideWebViewTests # on husky_fullmte
Change-Id: Ie238a015edba3c6ca2e1266cee9142b0d8927cc2