refactor(android): Make WRITE_EXTERNAL_STORAGE optional

[breautek]

Platforms affected

Android

Motivation and Context

Depends on #907

closes #861
closes #876

Across all API levels that we support, no permissions are necessary for reading from
gallery. This is because we use the Media Store and gain temporary access to the content.

Across all API levels that we support, no permissions are necessary for capturing an image from the camera. This is because we use an internal app cache directory and we grant the camera app to use this path.

Where permissions might be necessary is with the saveToPhotoAlbum option. If enabled, non scoped access devices (API 24-28) do require WRITE_EXTERNAL_STORAGE to write to the device's gallery. API 29+ with scoped access framework, no permissions are required.

This PR allows to be more modern on modern devices, and allows the user to opt into WRITE_EXTERNAL_STORAGE by providing the necessary config.xml directives, if they plan on using saveToPhotoAlbum option.

Users that don't want to save to the photo album does not need to declare any extra permissions.

Description

Reworked permission management so that WRITE_EXTERNAL_STORAGE is optional. READ_EXTERNAL_STORAGE is completely obsolete and has been removed.

The CAMERA permission workaround is still relevant across all API levels. If declared, the permission must be granted to use the camera intent and that workaround still remains.

Testing

Manual testing on API 28 & 34.
Paramedic test passes

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[erisu]

• Code changes LGTM
• Tested sample project
• Tested mobile spec