Fix NNAPI mlts test script to read output from /storage/emulated/0 instead
of /sdcard
The test Java code writes to Environment.getExternalStorageDirectory()
while the script has the path hardcoded.
Tested on several devices (including non-rooted) that they all return
the new path and it has read/write access.

Test: Ran script on several devices:
On Pixel 6 (non-rooted), Pixel 7 (rooted), Vivo x80 (non-rooted):
test/mlts/benchmark$ ./build_and_run_benchmark.sh -n arm -f arm-armnn-sl -x -s

Change-Id: Ibfe62084d238c44877e7e9e488b3ca13f0b7dd8b
diff --git a/build_and_run_benchmark.sh b/build_and_run_benchmark.sh
index 685d797..19206b0 100755
--- a/build_and_run_benchmark.sh
+++ b/build_and_run_benchmark.sh
@@ -282,7 +282,7 @@
   LOGDIR=$(mktemp -d)/mlts-logs
   HOST_CSV=$LOGDIR/benchmark.csv
   RESULT_HTML=$LOGDIR/result.html
-  DEVICE_CSV=/sdcard/mlts_benchmark.csv
+  DEVICE_CSV=/storage/emulated/0/mlts_benchmark.csv
 
   mkdir -p $LOGDIR
   echo Creating logs in $LOGDIR