Revert^2 "Generate a boot image extension for mainline BCP...

Revert submission 2465993-boot-image-mainline-revert

Reason for revert: Relanding the changes

Reverted changes: /q/submissionid:2465993-boot-image-mainline-revert

Change-Id: Ie611cf3a1ff4be7a7beab164f69b4186c474be5c
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index 373b478..f4827ea 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -291,6 +291,9 @@
 
 	// The "--compiler-filter" argument.
 	compilerFilter string
+
+	// The "--single-image" argument.
+	singleImage bool
 }
 
 // Target-dependent description of a boot image.
@@ -398,6 +401,9 @@
 		for _, ext := range exts {
 			ret = append(ret, dir.Join(ctx, name+ext))
 		}
+		if image.singleImage {
+			break
+		}
 	}
 	return ret
 }
@@ -768,6 +774,10 @@
 		cmd.FlagWithArg("--compiler-filter=", image.compilerFilter)
 	}
 
+	if image.singleImage {
+		cmd.Flag("--single-image")
+	}
+
 	// Use the default variant/features for host builds.
 	// The map below contains only device CPU info (which might be x86 on some devices).
 	if image.target.Os == android.Android {