Use -Werror in system/extras

* Use system-extras-cflags-defaults
* Move -Wall -Werror from cppflags to cflags
* fix warning on redefinition of MAX_PATH

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ib14b4d8eece767225a6fef639ed190b343678c00
diff --git a/ext4_utils/Android.bp b/ext4_utils/Android.bp
index 7bc2f00..ff17edb 100644
--- a/ext4_utils/Android.bp
+++ b/ext4_utils/Android.bp
@@ -2,6 +2,7 @@
 
 cc_library {
     name: "libext4_utils",
+    defaults: ["system-extras-cflags-defaults"],
     host_supported: true,
     srcs: [
         "make_ext4fs.c",