Revert "Generate the ART boot image for host as well (used by ART tests)."

This reverts commit e920d2d0c5f240f3a8c294dad48569460e62179c.

Reason for revert: b/157053931 - Broken test:
com.android.devicehealthchecks.SystemAppCheck#system_app_native_crash
on git_rvc-dev on crosshatch-userdebug at 6510182

This CL is the only change in this build range so seems likely to be
the culprit.

Build break bug number:
bug:157053931

Original CL bug numbers:
Bug: 147817558
Bug: 147819342
Bug: 156649984

Change-Id: If8bf2f646789b583adcbfbc5df263ce953c05b76
diff --git a/java/dexpreopt_config.go b/java/dexpreopt_config.go
index ffce2a9..f8356d1 100644
--- a/java/dexpreopt_config.go
+++ b/java/dexpreopt_config.go
@@ -61,10 +61,6 @@
 			targets = append(targets, target)
 		}
 	}
-	// We may also need the images on host in order to run host-based tests.
-	for _, target := range ctx.Config().Targets[android.BuildOs] {
-		targets = append(targets, target)
-	}
 
 	return targets
 }
@@ -149,7 +145,7 @@
 			// expands to <stem>.art for primary image and <stem>-<1st module>.art for extension
 			imageName := c.firstModuleNameOrStem() + ".art"
 
-			c.imageLocations = []string{c.dir.Join(ctx, "android", c.installSubdir, imageName).String()}
+			c.imageLocations = []string{c.dir.Join(ctx, c.installSubdir, imageName).String()}
 
 			// The path to bootclasspath dex files needs to be known at module
 			// GenerateAndroidBuildAction time, before the bootclasspath modules have been compiled.
@@ -164,7 +160,7 @@
 			// Create target-specific variants.
 			for _, target := range targets {
 				arch := target.Arch.ArchType
-				imageDir := c.dir.Join(ctx, target.Os.String(), c.installSubdir, arch.String())
+				imageDir := c.dir.Join(ctx, c.installSubdir, arch.String())
 				variant := &bootImageVariant{
 					bootImageConfig: c,
 					target:          target,