[Android] Maintain transparency in PNG images when picking & cropping

[GunnarAK]

Hi all,

Please feel free to suggest/make changes as I am not certain this PR is production ready.

Let's make this feature request a thing of the past!!

I'm using the following configuration:

const response = await ImageCropPicker.openPicker({
  mediaType: 'photo',
  cropping: true,
  enableRotationGesture: false,
  freeStyleCropEnabled: false,
  cropperActiveWidgetColor: theme.colors.accent,
  cropperChooseColor: '#007AFF', // iOS only
  cropperCancelColor: theme.colors.white, // iOS only
  height: 200,
  width: 200,
  compressImageQuality: 0.8,
  showCropFrame: isAndroid,
});

With this config I am able to:

• select a PNG image and maintain its transparency
• select a PNG Image, crop it, and maintain its transparency
• select a JPEG image, optionally crop it (just like before)

Related tickets:

• Allow to keep transparency in PNG images with alpha channel #1902
• Android transperent image getting black after uploaded #1558
• Response file extension and mime type is different  #649

Other tickets that will benefit from these changes (still need some work):

• [ENHANCEMENT] It should also return name of the image on Android as it returns on iOS (filename) in Response Object. #1376

[amazingSheeppp]

Thank you! That helped me