Make this build in Eclipse

Changing up custom extension mechanism to enable building in Eclipse.

Change-Id: I519c162a852abda0cc2b6d0b3f3bd4e8f53b6ad7
diff --git a/Android.mk b/Android.mk
index e443f12..1147f05 100644
--- a/Android.mk
+++ b/Android.mk
@@ -4,7 +4,7 @@
 # Include res dir from chips
 chips_dir := ../../../frameworks/ex/chips/res
 res_dirs := $(chips_dir) res
-src_dirs := src extensions_src
+src_dirs := src
 
 LOCAL_EMMA_COVERAGE_FILTER := +com.android.calendar.*