Use fdsan in direct channel registration

To help catch future bugs related to misuse of file descriptors.

Fixes: 244214188
Test: run test-sensorservice with & without fix for bug 234456046,
      confirm reliable crash without the fix + no crash with it
Test: atest CtsSensorTestCases
Change-Id: I7aca5830e02e6bde988e89d54e7008500d0db26f