Move adb_main to its own file.

Change-Id: If6e98c089b39f73bd8f4a878a82669bfeee367f3
diff --git a/adb/Android.mk b/adb/Android.mk
index 702300b..7ff4555 100644
--- a/adb/Android.mk
+++ b/adb/Android.mk
@@ -92,6 +92,7 @@
 
 LOCAL_SRC_FILES := \
 	adb.c \
+	adb_main.c \
 	console.c \
 	transport_local.c \
 	commandline.c \
@@ -141,6 +142,7 @@
 
 LOCAL_SRC_FILES := \
 	adb.c \
+	adb_main.c \
 	transport_local.c \
 	adb_auth_client.c \
 	sockets.c \