adbd/shell: grant access to sepolicy for cts

Test: Test: make cts && \
      cts-tradefed run singleCommand cts --skip-device-info \
      --skip-preconditions --skip-connectivity-check --abi arm64-v8a \
      --module CtsSecurityHostTestCases \
      -t android.security.cts.SELinuxHostTest#testNoExemptionsForBinderInVendorBan
      Fails as expected.
Bug: 36002573

Change-Id: I298c526789b25734d5f18666c64497e5d1e181d0