Don't hardcode bash location

bash may not be installed in /bin, so don't make that assumption.

Change-Id: I04ae786c7558f829ddf9649c127cbba1457dcfd3

contrib/git-exproll.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright (c) 2012, Code Aurora Forum. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without

gerrit-server/src/main/resources/com/google/gerrit/server/tools/root/scripts/reposize.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright (C) 2014 The Android Open Source Project
 #

tools/plugin_archetype_deploy.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright (C) 2014 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");

tools/util/query_tester.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 usage() {
     cat <<EOF