Replace extract-srcjars.sh with zipsync tool

extract_srcjars.sh uses zipinfo and unzip, which fail with an
error on an empty zip file.  Instead of trying to hack around
this (which is hard to make guarantees for since they are
non-hermetic host tools), replace them with a go tool to unzip
a set of zip files into a directory.

Bug: 73885582
Test: m checkbuild
Change-Id: I151fed347ed5196726e36866ffc27bc831799afb

scripts/extract-srcjars.sh

@@ -1,44 +0,0 @@
-#!/bin/bash -e
-
-# Copyright 2017 Google Inc. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# Extracts .java files from source jars in a specified directory and writes out a list of the files
-
-if [ -z "$1" -o -z "$2" ]; then
-  echo "usage: $0 <output dir> <output file> [<jar> ...]" >&2
-  exit 1
-fi
-
-output_dir=$1
-shift
-output_file=$1
-shift
-
-rm -f $output_file
-touch $output_file
-
-for j in "$@"; do
-  for f in $(zipinfo -1 $j '*.java'); do
-    echo $output_dir/$f >> $output_file
-  done
-  unzip -qn -d $output_dir $j '*.java'
-done
-
-duplicates=$(cat $output_file | sort | uniq -d | uniq)
-if [ -n "$duplicates" ]; then
-  echo Duplicate source files:
-  echo $duplicates
-  exit 1
-fi