liblouis: add -I$(LOCAL_PATH)/liblouis to CFLAGS to fix <config.h> include

Background:
Upstream liblouis recently switched to `#include <config.h>` instead of
`#include "config.h"`. This works fine with autotools builds because
`-I.` is always added to the compiler flags. However, in the Android NDK
build system `.` is not in the include path by default, which causes
build failures.

Fix:
Explicitly add -I$(LOCAL_PATH)/liblouis to LOCAL_CFLAGS so that <config.h>
is found during compilation. This keeps upstream sources untouched and
solves the issue cleanly in the build system layer.

Related upstream PR (proposed fix for using `"config.h"`):
liblouis/liblouis#1855

Signed-off-by: Patryk Miś <foss@patrykmis.com>

Author: PatrykMis

braille/translate/src/phone/jni/Android.mk

@@ -39,6 +39,7 @@ include $(CLEAR_VARS)
 LOCAL_PATH := $(LIBLOUIS_PATH)
 LOCAL_LDLIBS := -llog -landroid
 LOCAL_CFLAGS += -DTABLESDIR='"__non_existent_path__"'
+LOCAL_CFLAGS += -I$(LOCAL_PATH)/liblouis
 LOCAL_MODULE := louis
 LOCAL_SRC_FILES := \
   liblouis/compileTranslationTable.c \