fix(storage): pass StorageMetadata as nullable for putFile() API. Metadata ought to be inferred from File.

[russellwheatley]

Description

Storage emulator doesn't seem to infer type so I tested on the live project. Below shows uploading an image with and without changes from this PR which shows type inference is now working on android:

Related Issues

fixes #12570
fixes #12363

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[Lyokone]

Based on what we discussed, ie: inferring types doesn't work on the emulator, LGTM