cm: Bump version to 9.0.0-RC1

Change-Id: Ib92d58910d255af6090898772af6367c887835c2
diff --git a/config/common.mk b/config/common.mk
index 6b3e317..229dfec 100644
--- a/config/common.mk
+++ b/config/common.mk
@@ -118,7 +118,7 @@
 
 PRODUCT_VERSION_MAJOR = 9
 PRODUCT_VERSION_MINOR = 0
-PRODUCT_VERSION_MAINTENANCE = 0-RC0
+PRODUCT_VERSION_MAINTENANCE = 0-RC1
 
 # Set CM_BUILDTYPE
 ifdef CM_NIGHTLY