MTP FFS updates:

This update splits old MTP code and new MTP code from Google
into two trees, legacy and ffs. Depending on the SDK level,
the build system will select the correct version. The reason
for separating the versions out are due to older android trees
not supporting the updated MTP code from Google.

Most MTP code is from Google, with additions needed from
implementing the Java functions in C++ for TWRP and FFS.

We assume if you are in android-9.0 or above, your kernel
has support for FFS over MTP. Verify that your init.rc
is mounting the MTP FFS driver to the proper location.

Change-Id: I4b107b239bd9bc5699527f9c8c77d9079f264a7e

Android.mk

@@ -210,9 +210,19 @@ ifeq ($(shell git -C $(LOCAL_PATH) diff --quiet; echo $$?),1)
 endif
 LOCAL_CFLAGS += -DTW_GIT_REVISION='"$(tw_git_revision)"'
 
+ifeq ($(shell test $(PLATFORM_SDK_VERSION) -ge 28; echo $$?),0)
+ifeq ($(TW_EXCLUDE_MTP),)
+    LOCAL_SHARED_LIBRARIES += libtwrpmtp-ffs
+endif
+else
+ifeq ($(TW_EXCLUDE_MTP),)
+    LOCAL_CFLAGS += -DTW_HAS_LEGACY_MTP
+    LOCAL_SHARED_LIBRARIES += libtwrpmtp-legacy
+endif
+endif
+
 #TWRP Build Flags
 ifeq ($(TW_EXCLUDE_MTP),)
-    LOCAL_SHARED_LIBRARIES += libtwrpmtp
     LOCAL_CFLAGS += -DTW_HAS_MTP
 endif
 ifneq ($(TW_NO_SCREEN_TIMEOUT),)
@@ -783,6 +793,12 @@ ifeq ($(shell test $(PLATFORM_SDK_VERSION) -le 25; echo $$?),0)
 include $(commands_TWRP_local_path)/bootloader_message/Android.mk
 endif
 
+ifeq ($(shell test $(PLATFORM_SDK_VERSION) -ge 28; echo $$?),0)
+    include $(commands_TWRP_local_path)/mtp/ffs/Android.mk
+else
+    include $(commands_TWRP_local_path)/mtp/legacy/Android.mk
+endif
+
 ifeq ($(wildcard system/core/uncrypt/Android.mk),)
     #include $(commands_TWRP_local_path)/uncrypt/Android.mk
 endif
@@ -818,7 +834,6 @@ include $(commands_TWRP_local_path)/injecttwrp/Android.mk \
     $(commands_TWRP_local_path)/openaes/Android.mk \
     $(commands_TWRP_local_path)/toolbox/Android.mk \
     $(commands_TWRP_local_path)/twrpTarMain/Android.mk \
-    $(commands_TWRP_local_path)/mtp/Android.mk \
     $(commands_TWRP_local_path)/minzip/Android.mk \
     $(commands_TWRP_local_path)/dosfstools/Android.mk \
     $(commands_TWRP_local_path)/etc/Android.mk \