Revert "Make lots of tests run in parallel"

This reverts commit 323dc60712.

Reason for revert: Possible cause of test instability
Bug: 170513220
Test: soong tests

Change-Id: Iee168e9fbb4210569e6cffcc23e60d111403abb8

zip/zip_test.go

@@ -102,7 +102,6 @@ func fileArgsBuilder() *FileArgsBuilder {
 }
 
 func TestZip(t *testing.T) {
-	t.Parallel()
 	testCases := []struct {
 		name               string
 		args               *FileArgsBuilder
@@ -531,7 +530,6 @@ func TestZip(t *testing.T) {
 }
 
 func TestReadRespFile(t *testing.T) {
-	t.Parallel()
 	testCases := []struct {
 		name, in string
 		out      []string
@@ -604,7 +602,6 @@ func TestReadRespFile(t *testing.T) {
 }
 
 func TestSrcJar(t *testing.T) {
-	t.Parallel()
 	mockFs := pathtools.MockFs(map[string][]byte{
 		"wrong_package.java":       []byte("package foo;"),
 		"foo/correct_package.java": []byte("package foo;"),