Implement new NDK image decoding apis

Bug: 135133301
Test: Ib84462ea5fa8a7779eaa44494775e182e52ecaca

Separate out the code for encodedFormatToString into a piece which
returns a const char* that can be used by AImageDecoder (with its own
header) and the part that the JNI code uses to convert that into a Java
String.

Change-Id: I4cf8bfb0aacfb8e22c3f9b1689bd614ed1253673
diff --git a/native/graphics/jni/Android.bp b/native/graphics/jni/Android.bp
index d47de11..376ea77 100644
--- a/native/graphics/jni/Android.bp
+++ b/native/graphics/jni/Android.bp
@@ -25,16 +25,20 @@
     // our source files
     //
     srcs: [
-        "bitmap.cpp",
         "aassetstreamadaptor.cpp",
+        "bitmap.cpp",
+        "imagedecoder.cpp",
     ],
 
     shared_libs: [
         "libandroid",
         "libandroid_runtime",
+        "libhwui",
         "liblog",
     ],
 
+    static_libs: ["libarect"],
+
     arch: {
         arm: {
             // TODO: This is to work around b/24465209. Remove after root cause is fixed