Add bitmaps/native allocation metrics to 'dumpsys meminfo'

Bug: 331243037
Flag: com.android.libcore.native_metrics

Add metrics for Bitmaps, HardwareBuffer, and other objects with
native allocations associated to 'dumpsys meminfo'.

E.g.

$ adb shell dumpsys meminfo com.google.android.GoogleCamera

...

 Native Allocations
                         Count                      Total(kB)
                        ------                         ------
   Bitmap (malloced):       31                           6570
Bitmap (nonmalloced):        1                           2976
      HardwareBuffer:        5                           3681
   Others (malloced):     4133                            391
Others (nonmalloced):      391                            244

Change-Id: Ifa7dcc96806617cf378001b02b20a27208e0fbff