MainActivity add dropdown menu for CoT entity allegience and type

[mkrupczak3]

As a user, I want a dropdown menu for selecting Cursor on Target output entity allegiance and type, so that I do not have to change it and retransmit it again in the ATAK app every time.

For CoT Schema, see:

https://nps.edu/documents/104517539/109705106/COT+User+Guide.pdf/4e67c16d-171c-4f8c-9649-7b3870dbcb4c#page=9

[rdkgit]

Good idea. Kinda convoluted though. I'd love to copy whatever you come up with so I can add to iOS and Desktop.