Disable journaling to save system.img space.

Bug: 18430740
Change-Id: I80a3c8d71c27c1b0cb7bbf93e971674159e9e583
diff --git a/BoardConfigCommon.mk b/BoardConfigCommon.mk
index 064b98b..76cdf5f 100644
--- a/BoardConfigCommon.mk
+++ b/BoardConfigCommon.mk
@@ -39,6 +39,8 @@
 TARGET_USERIMAGES_USE_EXT4 := true
 
 BOARD_SYSTEMIMAGE_PARTITION_SIZE := 681574400
+# Disable journaling on system.img to save space.
+BOARD_SYSTEMIMAGE_JOURNAL_SIZE := 0
 BOARD_USERDATAIMAGE_PARTITION_SIZE := 6567231488
 BOARD_FLASH_BLOCK_SIZE := 4096