fix: DecodeForamt.RGB_565 not working

[yacyet]

Glide.with(this)
.load(url)
.format(DecodeFormat.PREFER_RGB_565);
When set 565 format, actually this does not work. This problem has discussed in #4461.
#4461

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[sjudd]

I'd rather not comment out code as a general practice.

That said, I think the issue here is fundamentally that the framework is claiming it's going to use ARGB_8888 when we ask it, even if we say we want RGB_565. We might choose to ignore outConfig entirely, but I'm not sure that's the best idea. After all there may be cases where the framework can actually only produce ARGB_8888.

I think there's two things to do:

1. File a framework bug if we use inPreferredConfig = RGB_565, inJustDecodeBounds=true, outConfig gives us ARGB_8888, but if we provide an input Bitmap with RGB_565 the decode just works fine. Preferably we'd have a test case for this
2. Up until whenever the framework bug in Bitmap pool is count not size limited #1 is fixed, in Glide, try to decode with RGB_565 even if outConfig gives us ARGB_8888, but being sure to retry with ARGB_8888 if our RGB_565 load fails.

The best place to start is probably tests, rather than code. There's a bunch here, maybe we could add a new one or two? https://github.com/bumptech/glide/tree/master/instrumentation

[yacyet]

Got it, thanks!