Consolidate OfflineRegionDefintions

[tobrun]

Follow up from #11447, where we weren't able to address the issue below due to semver.

With next major version bump, we should consolidate the implementations of OfflineRegionDefintion and increase the API surface of the OfflineRegionDefinition interface. Atm we have two concrete implementations of this interface:

• OfflineTilePyramidRegionDefinition
• OfflineGeometryRegionDefinition

These implementations share a lot of similar concepts but aren't found in the OfflineRegionDefinition. This results in writing boilerplate as below to support both implementations:

    if (definition instanceof OfflineTilePyramidRegionDefinition) {
      OfflineTilePyramidRegionDefinition regionDefinition = (OfflineTilePyramidRegionDefinition) definition;
      styleUrl =  regionDefinition.getStyleURL();
      minZoom = regionDefinition.getMinZoom();
      maxZoom = regionDefinition.getMaxZoom();
      cameraPosition = new CameraPosition.Builder()
        .target(regionDefinition.getBounds().getCenter())
        .zoom(minZoom)
        .build();
    } else if (definition instanceof OfflineGeometryRegionDefinition) {
      OfflineGeometryRegionDefinition regionDefinition = (OfflineGeometryRegionDefinition) definition;
      styleUrl = regionDefinition.getStyleURL();
      minZoom = regionDefinition.getMinZoom();
      maxZoom = regionDefinition.getMaxZoom();
      cameraPosition = new CameraPosition.Builder()
        .target(regionDefinition.getBounds().getCenter())
        .zoom(minZoom)
        .build();
    }

I'm suggesting altering the OfflineRegionDefinition to include:

• styleUrl
• minZoom
• maxZoom
• initial camera position
• ...

[tobrun]

landed with #13237