Set BOARD_X_FILE_SYSTEM_TYPE in the common BoardConfig file

required if TARGET_COPY_OUT_X is set to
`product` or `system_ext`.

Bug: 111538404
Test: presubmit
Change-Id: Ibe7538885cd2f00b8f4340db83be7618a0beee4a
Signed-off-by: Roman Kiryanov <rkir@google.com>
diff --git a/target/board/BoardConfigMainlineCommon.mk b/target/board/BoardConfigMainlineCommon.mk
index 00f6e5b..e5ac5cf 100644
--- a/target/board/BoardConfigMainlineCommon.mk
+++ b/target/board/BoardConfigMainlineCommon.mk
@@ -14,6 +14,8 @@
 TARGET_COPY_OUT_SYSTEM_EXT := system_ext
 TARGET_COPY_OUT_VENDOR := vendor
 TARGET_COPY_OUT_PRODUCT := product
+BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE := ext4
+BOARD_SYSTEM_EXTIMAGE_FILE_SYSTEM_TYPE := ext4
 
 # Creates metadata partition mount point under root for
 # the devices with metadata parition