[ART] Make killing logd more safe

The current behaviour of 'killall -9 /system/bin/logd' is different for the
master branch and for stable android-9.0.0 branches. For the master branch it
works as expected but for the android-9.0.0 branches it causes devices
to reboot.

This CL replaces 'killall -9 /system/bin/logd' with 'pkill -9 -U logd logd'.

Test: Device with AOSP master, setup-buildbot-device.sh, no 'waiting for device' massages
Test: Device with AOSP android-9.0.0_r6, setup-buildbot-device.sh, no 'waiting for device' messages
Change-Id: I1e33f0c2705c8173c6b29658833d00cf9f345d6f
diff --git a/tools/setup-buildbot-device.sh b/tools/setup-buildbot-device.sh
index 04e80df..ef958d6 100755
--- a/tools/setup-buildbot-device.sh
+++ b/tools/setup-buildbot-device.sh
@@ -43,7 +43,7 @@
 # Kill logd first, so that when we set the adb buffer size later in this file,
 # it is brought up again.
 echo -e "${green}Killing logd, seen leaking on fugu/N${nc}"
-adb shell killall -9 /system/bin/logd
+adb shell pkill -9 -U logd logd && echo -e "${green}...logd killed${nc}"
 
 # Update date on device if the difference with host is more than one hour.
 if [ $abs_time_difference_in_seconds -gt $seconds_per_hour ]; then