Add --proguard option to metalava

Also clean-up properties comments

Test: m -j docs
Bug: b/78245848
Change-Id: I43899e9841e0d29e5be7ab2b393cc78186970231
diff --git a/java/droiddoc.go b/java/droiddoc.go
index e9b7c0e..bfe72f6 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -307,31 +307,34 @@
 	// the tag name used to distinguish if the API files belong to public/system/test.
 	Api_tag_name *string
 
-	// the generated public API filename by Doclava.
+	// the generated public API filename by Metalava.
 	Api_filename *string
 
-	// the generated public Dex API filename by Doclava.
+	// the generated public Dex API filename by Metalava.
 	Dex_api_filename *string
 
-	// the generated private API filename by Doclava.
+	// the generated private API filename by Metalava.
 	Private_api_filename *string
 
-	// the generated private Dex API filename by Doclava.
+	// the generated private Dex API filename by Metalava.
 	Private_dex_api_filename *string
 
-	// the generated removed API filename by Doclava.
+	// the generated removed API filename by Metalava.
 	Removed_api_filename *string
 
-	// the generated removed Dex API filename by Doclava.
+	// the generated removed Dex API filename by Metalava.
 	Removed_dex_api_filename *string
 
 	// mapping of dex signatures to source file and line number. This is a temporary property and
 	// will be deleted; you probably shouldn't be using it.
 	Dex_mapping_filename *string
 
-	// the generated exact API filename by Doclava.
+	// the generated exact API filename by Metalava.
 	Exact_api_filename *string
 
+	// the generated proguard filename by Metalava.
+	Proguard_filename *string
+
 	Check_api struct {
 		Last_released ApiToCheck
 
@@ -1213,6 +1216,7 @@
 	removedDexApiFile      android.WritablePath
 	apiMappingFile         android.WritablePath
 	exactApiFile           android.WritablePath
+	proguardFile           android.WritablePath
 
 	checkCurrentApiTimestamp      android.WritablePath
 	updateCurrentApiTimestamp     android.WritablePath
@@ -1363,6 +1367,12 @@
 		*implicitOutputs = append(*implicitOutputs, d.apiMappingFile)
 	}
 
+	if String(d.properties.Proguard_filename) != "" {
+		d.proguardFile = android.PathForModuleOut(ctx, String(d.properties.Proguard_filename))
+		metalavaFlags += " --proguard " + d.proguardFile.String()
+		*implicitOutputs = append(*implicitOutputs, d.proguardFile)
+	}
+
 	if Bool(d.properties.Write_sdk_values) {
 		metalavaFlags = metalavaFlags + " --sdk-values " + android.PathForModuleOut(ctx, "out").String()
 	}