All Bitmap constructors have been made private and the only way to
create one is through the allocate or createFrom factories.
SkColorSpace is now explicitly passed in to all the factories and is
no longer assumed to be sRGB.
Test: atest CtsGraphicsTestCases
Change-Id: I92c1c5c59df6de7fdd90e9504a2c2717cb854588
e216948d63