[ndk-build] Using newer version of ndk-build for the tests

Summary: Using the newest version of ndk-build (r15c) for the tests

Reviewed By: jvillard

Differential Revision: D5755792

fbshipit-source-id: 544bd09

configure.ac

@@ -300,7 +300,7 @@ if test x"$NDKBUILD" = x"no"; then
 # ndk-build not in $PATH, look into potential android NDK install paths and record the absolute path
 # to ndk-build
   AC_PATH_PROG([NDKBUILD], [ndk-build], [no],
-    [$PATH$PATH_SEPARATOR$ANDROID_NDK$PATH_SEPARATOR/opt/android_ndk/r10e])
+    [$PATH$PATH_SEPARATOR$ANDROID_NDK$PATH_SEPARATOR/opt/android_ndk/r15c])
 fi
 
 AC_CHECK_PYTHON_MODULE([$PYTHON27], [lxml])