Add a --symlinks argument to soong_zip

Add a --symlinks argument that defaults to true to soong_zip.
Passing --symlinks=false will cause it to follow symlinks instead
of storing them in the zip file.

Relands I4deb98daa9d4ba9f94e3d7670c117fe00381d2ba with tests.

Bug: 112843624
Test: glob_test.go
Test: zip_test.go
Test: m checkbuild
Change-Id: I0eff9c1f2dba79e873fda381ff585df55d5aaaad

zip/zip_test.go

@@ -105,6 +105,7 @@ func TestZip(t *testing.T) {
 		nonDeflatedFiles map[string]bool
 		dirEntries       bool
 		manifest         string
+		storeSymlinks    bool
 
 		files []zip.FileHeader
 		err   error
@@ -135,6 +136,7 @@ func TestZip(t *testing.T) {
 				SourcePrefixToStrip("a").
 				File("a/**/*"),
 			compressionLevel: 9,
+			storeSymlinks:    true,
 
 			files: []zip.FileHeader{
 				fh("a/a", fileA, zip.Deflate),
@@ -149,6 +151,7 @@ func TestZip(t *testing.T) {
 				SourcePrefixToStrip("a").
 				Dir("a"),
 			compressionLevel: 9,
+			storeSymlinks:    true,
 
 			files: []zip.FileHeader{
 				fh("a/a", fileA, zip.Deflate),
@@ -179,6 +182,7 @@ func TestZip(t *testing.T) {
 				File("a/a/c").
 				File("a/a/d"),
 			compressionLevel: 9,
+			storeSymlinks:    true,
 
 			files: []zip.FileHeader{
 				fh("a/a/a", fileA, zip.Deflate),
@@ -187,6 +191,23 @@ func TestZip(t *testing.T) {
 				fhLink("a/a/d", "b"),
 			},
 		},
+		{
+			name: "follow symlinks",
+			args: fileArgsBuilder().
+				File("a/a/a").
+				File("a/a/b").
+				File("a/a/c").
+				File("a/a/d"),
+			compressionLevel: 9,
+			storeSymlinks:    false,
+
+			files: []zip.FileHeader{
+				fh("a/a/a", fileA, zip.Deflate),
+				fh("a/a/b", fileB, zip.Deflate),
+				fh("a/a/c", fileC, zip.Deflate),
+				fh("a/a/d", fileB, zip.Deflate),
+			},
+		},
 		{
 			name: "list",
 			args: fileArgsBuilder().
@@ -359,6 +380,7 @@ func TestZip(t *testing.T) {
 			args.AddDirectoryEntriesToZip = test.dirEntries
 			args.NonDeflatedFiles = test.nonDeflatedFiles
 			args.ManifestSourcePath = test.manifest
+			args.StoreSymlinks = test.storeSymlinks
 			args.Filesystem = mockFs
 
 			buf := &bytes.Buffer{}