Create symlink in the case where device has no cache partition

Create symlink from /cache to /data/cache for devices
which have no cache partition.

Bug: 28747374
Change-Id: Ifb0c3250f1be345ce46fcdb78533e36c2250bb85
diff --git a/rootdir/Android.mk b/rootdir/Android.mk
index d53af2f..fd2b8b0 100644
--- a/rootdir/Android.mk
+++ b/rootdir/Android.mk
@@ -54,7 +54,7 @@
 #
 # create some directories (some are mount points) and symlinks
 LOCAL_POST_INSTALL_CMD := mkdir -p $(addprefix $(TARGET_ROOT_OUT)/, \
-    sbin dev proc sys system data oem acct cache config storage mnt root $(BOARD_ROOT_EXTRA_FOLDERS)); \
+    sbin dev proc sys system data oem acct config storage mnt root $(BOARD_ROOT_EXTRA_FOLDERS)); \
     ln -sf /system/etc $(TARGET_ROOT_OUT)/etc; \
     ln -sf /sys/kernel/debug $(TARGET_ROOT_OUT)/d; \
     ln -sf /storage/self/primary $(TARGET_ROOT_OUT)/sdcard
@@ -63,6 +63,11 @@
 else
   LOCAL_POST_INSTALL_CMD += ; ln -sf /system/vendor $(TARGET_ROOT_OUT)/vendor
 endif
+ifdef BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE
+  LOCAL_POST_INSTALL_CMD += ; mkdir -p $(TARGET_ROOT_OUT)/cache
+else
+  LOCAL_POST_INSTALL_CMD += ; ln -sf /data/cache $(TARGET_ROOT_OUT)/cache
+endif
 ifdef BOARD_ROOT_EXTRA_SYMLINKS
 # BOARD_ROOT_EXTRA_SYMLINKS is a list of <target>:<link_name>.
   LOCAL_POST_INSTALL_CMD += $(foreach s, $(BOARD_ROOT_EXTRA_SYMLINKS),\