Dynamic logs for motions in UnwantedInteractionBlocker

Currently, we have no way to debug the palm rejection operation in real
time. On some devices, we are observing touches rejected unreasonably.

For improved debugging, provide a way to turn on the logs at runtime.

Sample logs:
07-29 20:50:51.938 21364 21461 D UnwantedInteractionBlocker: notifyMotion: NotifyMotionArgs(id=437279320, eventTime=681206765436000, deviceId=4, source=TOUCHSCREEN, action=MOVE, pointerCount=2 pointers={0: id=0 x=1998.0 y=732.0 pressure=1.0 major=78.0 minor=78.0 orientation=1.6}, {1: id=1 x=1651.0 y=705.0 pressure=0.5 major=14.0 minor=14.0 orientation=1.6}, flags=0x00000000)
07-29 20:50:51.939 21364 21461 D UnwantedInteractionBlocker: Filter: touches = 0 : InProgressTouchEvdev(x=1998, y=732, tracking_id=0, slot=0, pressure=0.996094, major=78, minor=78, tool_type=0, altered=1, was_touching=1, touching=1)
07-29 20:50:51.939 21364 21461 D UnwantedInteractionBlocker: 1 : InProgressTouchEvdev(x=1651, y=705, tracking_id=1, slot=1, pressure=0.546875, major=14, minor=14, tool_type=0, altered=1, was_touching=1, touching=1)
07-29 20:50:51.939 21364 21461 D UnwantedInteractionBlocker: Response: slotsToHold = 00000000000000000000, slotsToSuppress = 00000000000000000011
07-29 20:50:51.939 21364 21461 I UnwantedInteractionBlocker: Palm detected, removing pointer ids {0, 1} after 656ms from NotifyMotionArgs(id=437279320, eventTime=681206765436000, deviceId=4, source=TOUCHSCREEN, action=MOVE, pointerCount=2 pointers={0: id=0 x=1998.0 y=732.0 pressure=1.0 major=78.0 minor=78.0 orientation=1.6}, {1: id=1 x=1651.0 y=705.0 pressure=0.5 major=14.0 minor=14.0 orientation=1.6}, flags=0x00000000)
07-29 20:50:51.939 21364 21461 D UnwantedInteractionBlocker: enqueueOutboundMotionLocked: NotifyMotionArgs(id=437279320, eventTime=681206765436000, deviceId=4, source=TOUCHSCREEN, action=CANCEL, pointerCount=1 pointers={0: id=1 x=1651.0 y=705.0 pressure=0.5 major=14.0 minor=14.0 orientation=1.6}, flags=0x00000020)
07-29 20:50:51.947 21364 21461 D UnwantedInteractionBlocker: notifyMotion: NotifyMotionArgs(id=1057496278, eventTime=681206774728000, deviceId=4, source=TOUCHSCREEN, action=MOVE, pointerCount=2 pointers={0: id=0 x=1996.0 y=732.0 pressure=1.0 major=78.0 minor=78.0 orientation=1.6}, {1: id=1 x=1651.0 y=705.0 pressure=0.5 major=14.0 minor=14.0 orientation=1.6}, flags=0x00000000)
07-29 20:50:51.947 21364 21461 D UnwantedInteractionBlocker: Filter: touches = 0 : InProgressTouchEvdev(x=1996, y=732, tracking_id=0, slot=0, pressure=0.996094, major=78, minor=78, tool_type=0, altered=1, was_touching=1, touching=1)
07-29 20:50:51.947 21364 21461 D UnwantedInteractionBlocker: 1 : InProgressTouchEvdev(x=1651, y=705, tracking_id=1, slot=1, pressure=0.542969, major=14, minor=14, tool_type=0, altered=1, was_touching=1, touching=1)
07-29 20:50:51.948 21364 21461 D UnwantedInteractionBlocker: Response: slotsToHold = 00000000000000000000, slotsToSuppress = 00000000000000000011

Bug: 239463037
Bug: 198472780
Test: looked at the logs with palm rejection enabled
Change-Id: I10e54bd0c4ca26fd6197b3ff0069f9799ea91ccf