Remove android_info's timestamp file

The build rule was removed in aosp/3453258, but the usages weren't.

Bug: 376727180
Test: m --soong-only
Change-Id: I03330cdaaf4cbe78b159b5b6b480518b0ae4c7e1
diff --git a/android/android_info.go b/android/android_info.go
index 561fa4c..9a68d10 100644
--- a/android/android_info.go
+++ b/android/android_info.go
@@ -58,19 +58,17 @@
 	androidInfoTxtName := proptools.StringDefault(p.properties.Stem, ctx.ModuleName()+".txt")
 	androidInfoTxt := PathForModuleOut(ctx, androidInfoTxtName)
 	androidInfoProp := androidInfoTxt.ReplaceExtension(ctx, "prop")
-	timestamp := PathForModuleOut(ctx, "timestamp")
 
 	if boardInfoFiles := PathsForModuleSrc(ctx, p.properties.Board_info_files); len(boardInfoFiles) > 0 {
 		ctx.Build(pctx, BuildParams{
-			Rule:       mergeAndRemoveComments,
-			Inputs:     boardInfoFiles,
-			Output:     androidInfoTxt,
-			Validation: timestamp,
+			Rule:   mergeAndRemoveComments,
+			Inputs: boardInfoFiles,
+			Output: androidInfoTxt,
 		})
 	} else if bootloaderBoardName := proptools.String(p.properties.Bootloader_board_name); bootloaderBoardName != "" {
-		WriteFileRule(ctx, androidInfoTxt, "board="+bootloaderBoardName, timestamp)
+		WriteFileRule(ctx, androidInfoTxt, "board="+bootloaderBoardName)
 	} else {
-		WriteFileRule(ctx, androidInfoTxt, "", timestamp)
+		WriteFileRule(ctx, androidInfoTxt, "")
 	}
 
 	// Create android_info.prop