Revert "Consistently use either "boot" or "apex" boot image as the default."

This reverts commit 48b3b3c71f76fa05de191b8460a186e9dbcc36bf.

Reason for revert: breaks emulator

BUG: 146558375

Change-Id: I2af3d11ad9a014b0d73a73540bc814f245bc6418
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index 5714531..1d363c9 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -220,19 +220,16 @@
 		return
 	}
 
-	// Default boot image is either the framework one, or the JIT-zygote one.
-	// The boot image that is created first is used to get a unique profile rule for all images.
-	if global.GenerateApexImage {
-		d.defaultBootImage = buildBootImage(ctx, apexBootImageConfig(ctx))
-		d.otherImages = append(d.otherImages, buildBootImage(ctx, frameworkBootImageConfig(ctx)))
-	} else {
-		d.defaultBootImage = buildBootImage(ctx, frameworkBootImageConfig(ctx))
-	}
-
-	// Create the ART boot image.
+	// Always create the default boot image first, to get a unique profile rule for all images.
+	d.defaultBootImage = buildBootImage(ctx, defaultBootImageConfig(ctx))
 	if !skipDexpreoptArtBootJars(ctx) {
+		// Create boot image for the ART apex (build artifacts are accessed via the global boot image config).
 		d.otherImages = append(d.otherImages, buildBootImage(ctx, artBootImageConfig(ctx)))
 	}
+	if global.GenerateApexImage {
+		// Create boot images for the JIT-zygote experiment.
+		d.otherImages = append(d.otherImages, buildBootImage(ctx, apexBootImageConfig(ctx)))
+	}
 
 	dumpOatRules(ctx, d.defaultBootImage)
 }