Adding TARGET_OTA_ASSERT_DEVICE flag for custom device asserts

Should be handled via device tree's BoardConfig
Sample will be TARGET_OTA_ASSERT_DEVICE := le_zl1,zl1,lepro3,lex720,lex727,LEX720,LEX727 in BoardConfig
Only applicable for AB or VAB devices

Change-Id: I1fbe6155d3f79eee089a31dbe62ee9d04c33d65c
(cherry picked from commit 45a8d148b51fc351d6b6dff05bd97ebe7c631b3d)
diff --git a/Android.mk b/Android.mk
index 5ed965e..2f2520a 100755
--- a/Android.mk
+++ b/Android.mk
@@ -398,6 +398,9 @@
 ifeq ($(TW_EXCLUDE_NANO), true)
     LOCAL_CFLAGS += -DTW_EXCLUDE_NANO
 endif
+ifneq ($(TARGET_OTA_ASSERT_DEVICE),)
+    LOCAL_CFLAGS += -DTARGET_OTA_ASSERT_DEVICE='"$(TARGET_OTA_ASSERT_DEVICE)"'
+endif
 
 LOCAL_C_INCLUDES += system/vold \