[android] Polygon holes

[Guardiola31337]

New attempt of fixing #1729

• Support for 1 hole
  • Support in Polygon
  • Support in PolygonOptions
• Support for multiple holes

@ivovandongen Could you review/add more comments on C++ part?
At the moment, still remains the following:

• Tweak C++ code
  • Naming
  • Use of aliases?
  • Separate the implementation in an implementation file
  • Separate the concerns in multiple methods

Anything else?

BTW, does the overall PR make sense? Would you tackle it using a different approach?

[ivovandongen]

I think we should take into consideration that there can be multiple (non-overlapping) holes.

[1ec5]

For reference, #7397 attempted to support multiple holes at the Java level, and mbgl does support multiple holes (as seen on iOS and macOS); it’s the JNI part that apparently wasn’t working.

[ivovandongen]

👍