Add attachinfo information to ViewRootImpl dump

Currently, we are dumping information on ViewRootImpl, but it doesn't
include some of the critical pieces. Add attachinfo information. Also,
attach a dump of a variable that determines whether the input events
will be dropped.

Example of newly added piece of dumpsys:

      mPausedForTransition=false
      ...
      mAttachInfo=       AttachInfo:
        mHasWindowFocus=true
        mWindowVisibility=0
        mInTouchMode=true
        mUnbufferedDispatchRequested=false

Bug: 173675649
Test: adb shell dumpsys activity -v all
Change-Id: I7b8801436f74a123bf96735de30b238146413545