Support manifest fragments.

LOCAL_VINTF_FRAGMENTS/vintf_fragments are
used to specify what manifest fragments should be installed
by a target.

Test: fragments get installed to the right location
Test: broken fragment gets detected
Test: boot device and verify service is working and manifest is updated
Test: verify OTA package contains fragments
Bug: 66917623
Change-Id: I21abe65a31b8c3d255c8ccd80e102ff3acb23105
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index d1ba354..eccaad5 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -267,6 +267,7 @@
 LOCAL_USE_R8:=
 LOCAL_USE_VNDK:=
 LOCAL_VENDOR_MODULE:=
+LOCAL_VINTF_FRAGMENTS:=
 LOCAL_VTSC_FLAGS:=
 LOCAL_VTS_INCLUDES:=
 LOCAL_VTS_MODE:=