docs: update Android docs build to include API 22, Android 5.1

Change-Id: If41c1a142db0f2df439afaa9cf5d0fe0ca47d2c0
diff --git a/Android.mk b/Android.mk
index 0ba92cf..3b1991c 100644
--- a/Android.mk
+++ b/Android.mk
@@ -715,6 +715,7 @@
     -since $(SRC_API_DIR)/19.txt 19 \
     -since $(SRC_API_DIR)/20.txt 20 \
     -since $(SRC_API_DIR)/21.txt 21 \
+    -since $(SRC_API_DIR)/22.txt 22 \
 		-werror -hide 111 -hide 113 \
 		-overview $(LOCAL_PATH)/core/java/overview.html
 
@@ -751,7 +752,7 @@
 
 ## SDK version identifiers used in the published docs
   # major[.minor] version for current SDK. (full releases only)
-framework_docs_SDK_VERSION:=4.4
+framework_docs_SDK_VERSION:=5.1
   # release version (ie "Release x")  (full releases only)
 framework_docs_SDK_REL_ID:=1