[android] - add heatmap color property

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/HeatmapLayer.java

@@ -167,6 +167,32 @@ public class HeatmapLayer extends Layer {
     nativeSetHeatmapIntensityTransition(options.getDuration(), options.getDelay());
   }
 
+  /**
+   * Get the HeatmapColor property
+   *
+   * @return property wrapper value around String
+   */
+  @SuppressWarnings("unchecked")
+  public PropertyValue<String> getHeatmapColor() {
+    return (PropertyValue<String>) new PropertyValue("heatmap-color", nativeGetHeatmapColor());
+  }
+
+  /**
+   * Defines the color of each pixel based on its density value in a heatmap.  Should be an expression that uses `["heatmap-density"]` as input.
+   *
+   * @return int representation of a rgba string color
+   * @throws RuntimeException thrown if property isn't a value
+   */
+  @ColorInt
+  public int getHeatmapColorAsInt() {
+    PropertyValue<String> value = getHeatmapColor();
+    if (value.isValue()) {
+      return rgbaToColor(value.getValue());
+    } else {
+      throw new RuntimeException("heatmap-color was set as a Function");
+    }
+  }
+
   /**
    * Get the HeatmapOpacity property
    *
@@ -209,6 +235,8 @@ public class HeatmapLayer extends Layer {
 
   private native void nativeSetHeatmapIntensityTransition(long duration, long delay);
 
+  private native Object nativeGetHeatmapColor();
+
   private native Object nativeGetHeatmapOpacity();
 
   private native TransitionOptions nativeGetHeatmapOpacityTransition();

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/PropertyFactory.java

@@ -1614,6 +1614,36 @@ public class PropertyFactory {
     return new PaintPropertyValue<>("heatmap-intensity", function);
   }
 
+  /**
+   * Defines the color of each pixel based on its density value in a heatmap.  Should be an expression that uses `["heatmap-density"]` as input.
+   *
+   * @param value a int color value
+   * @return property wrapper around String color
+   */
+  public static PropertyValue<String> heatmapColor(@ColorInt int value) {
+    return new PaintPropertyValue<>("heatmap-color", colorToRgbaString(value));
+  }
+
+  /**
+   * Defines the color of each pixel based on its density value in a heatmap.  Should be an expression that uses `["heatmap-density"]` as input.
+   *
+   * @param value a String value
+   * @return property wrapper around String
+   */
+  public static PropertyValue<String> heatmapColor(String value) {
+    return new PaintPropertyValue<>("heatmap-color", value);
+  }
+
+  /**
+   * Defines the color of each pixel based on its density value in a heatmap.  Should be an expression that uses `["heatmap-density"]` as input.
+   *
+   * @param expression an expression statement
+   * @return property wrapper around an expression statement
+   */
+  public static PropertyValue<Expression> heatmapColor(Expression expression) {
+    return new PaintPropertyValue<>("heatmap-color", expression);
+  }
+
   /**
    * The global opacity at which the heatmap layer will be drawn.
    *