Switch back to the binary camera HAL

Add compatibility libutils symbols required by it, and use it
again. It's much more reliable than the reimplementation

Change-Id: Ic837f4688015a956d635f0cf6b9846c24265a4e1
SELinux: Remove duplicate rules

These are now declared in the global sepolicy

Change-Id: I2861d939a43e0f7b736534006b83505fe52fbd35
Camera2: Don't try to cancel focus messages when preview stops

Change-Id: I3dc4762de2b321f3d01d6d6c07ec5fba33fb90e5