Mime package does not recognize 3gp4 and 3gp2 magic numbers

[Xentraxx]

A user reported the following issue: Xentraxx/GooglePhotosTakeoutHelper#60

I ran some tests and noticed that
[0x00, 0x00, 0x00, 0x14, 0x66, 0x74, 0x79, 0x70, 0x33, 0x67, 0x70, 0x34] (magic number for 3gp4) is not being detected as 3gp.

[0x00, 0x00, 0x00, 0x14, 0x66, 0x74, 0x79, 0x70, 0x33, 0x67, 0x70, 0x32] (magic number for 3gp2) is not being detected as 3gp.

In both cases, the mime package incorrectly returns "video/mp4".

However,
[0x00, 0x00, 0x00, 0x14, 0x66, 0x74, 0x79, 0x70, 0x33, 0x67, 0x70, 0x35] (magic number for 3gp5) is being detected as 3gp (returns "video/3gpp").

The last 3 bytes are the brand identifiers.

So to summarize, the mime package doesn't correctly return the 3gp mime type for 3gp4 and 3gp2 files. Only 3gp5 is being detected correctly.