Represent action as text in dumpsys

Currently, bugreports contain numbers for action information, which is
difficult to read. Make this easier by converting action number into the
actual string for the definition.

Bug: 64258224
Test: touch the screen, then run "adb shell dumpsys input". Observe the
RecentQueue events: action should be represented as a string.

Change-Id: I2346441a482a3016aa7e3ea5dacf2ae3b487fbcb
Merged-In: I2346441a482a3016aa7e3ea5dacf2ae3b487fbcb