Bitmap Model

The value of the Bitmap model is the sum of bytes used for native pixel data
of instances of android.graphics.Bitmap. It is calculated by summing for
each instance x of android.graphics.Bitmap:

x.getAllocationByteCount()

The actionable breakdown of the Bitmap model is a breakdown by
android.graphics.Bitmap instance, including width, height, and ideally a
thumbnail image of each bitmap.

For example, an 800 x 600 bitmap instance using the ARGB_8888 pixel format
with native pixel data will be shown as an 800 x 600 bitmap instance taking up
1875 kB.