Apply "excludes" for OutputFileProducer

"excludes" should be applied both SourceFileProducer and
OutputFileProducer. But we've been missing the latter.
(see android/paths_test.go)

There's one more to note. Previously, the exclusion was done by
modifying slice directly, which caused some problem(b/76179848).
The fix was returning a copy from Srcs() method. But there're still many
implementors which just return internal slices directly.

This change creates a new array when it needs to exclude something from
returned slice.

Bug: n/a
Test: m (soong test added)
Change-Id: I1ba91e490cb55fc243020681667278cdc75f59df

android/paths_test.go

@@ -1090,6 +1090,21 @@ func TestPathsForModuleSrc(t *testing.T) {
 			srcs: []string{buildDir + "/.intermediates/ofp/b/gen/c"},
 			rels: []string{"gen/c"},
 		},
+		{
+			name: "output file provider with exclude",
+			bp: `
+			test {
+				name: "foo",
+				srcs: [":b", ":c"],
+				exclude_srcs: [":c"]
+			}
+			output_file_provider {
+				name: "c",
+				outs: ["gen/c"],
+			}`,
+			srcs: []string{buildDir + "/.intermediates/ofp/b/gen/b"},
+			rels: []string{"gen/b"},
+		},
 		{
 			name: "special characters glob",
 			bp: `