android: Get the port up and running again

The build system needed fixes because the tools paths changed and one tool that
we used (apkbuilder) was removed entirely. Recent NDKs don't ship gcc 4.4.3
anymore, therefore switch to 4.6. The code itself needed a fix for a jni
reference bug that was uncovered by KitKat.

The port now builds with latest sdk (r22) and ndk (r9d).

Change-Id: Id74fa54ba93bbb0ee30373fbe79e92c5ff03201d
diff --git a/android/project.properties b/android/project.properties
index 895c9ce..a5578ba 100644
--- a/android/project.properties
+++ b/android/project.properties
@@ -8,4 +8,4 @@
 # project structure.
 
 # Project target.
-target=android-16
+target=android-19