Rename fields in dexpreopt config

Add 'host' into the name of fields regarding path on the host side to
distinguish between paths on the device(which will be added in the
following commit), and paths on the host.

Bug: 158843648
Test: build and flash, and then
  adb wait-for-device \
    && adb -s $S root \
    && adb -s $S logcat \
    | grep -E 'ClassLoaderContext [a-z ]+ mismatch' -C 1
Change-Id: Ib2645ed51591ba2f4b726c115b401ad2bd6675da
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index f85e1c9..19d1075 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -242,7 +242,7 @@
 	symbolsDir android.OutputPath
 
 	// Subdirectory where the image files are installed.
-	installSubdir string
+	installDirOnHost string
 
 	// A list of (location, jar) pairs for the Java modules in this image.
 	modules android.ConfiguredJarList
@@ -273,8 +273,8 @@
 	dexLocationsDeps []string // for the dependency images and in this image
 
 	// Paths to image files.
-	images     android.OutputPath  // first image file
-	imagesDeps android.OutputPaths // all files
+	imagePathOnHost android.OutputPath  // first image file
+	imagesDeps      android.OutputPaths // all files
 
 	// Only for extensions, paths to the primary boot images.
 	primaryImages android.OutputPath
@@ -365,7 +365,7 @@
 	if image.extends != nil {
 		imageLocations = image.extends.getVariant(image.target).imageLocations()
 	}
-	return append(imageLocations, dexpreopt.PathToLocation(image.images, image.target.Arch.ArchType))
+	return append(imageLocations, dexpreopt.PathToLocation(image.imagePathOnHost, image.target.Arch.ArchType))
 }
 
 func dexpreoptBootJarsFactory() android.SingletonModule {
@@ -656,9 +656,9 @@
 
 	arch := image.target.Arch.ArchType
 	os := image.target.Os.String() // We need to distinguish host-x86 and device-x86.
-	symbolsDir := image.symbolsDir.Join(ctx, os, image.installSubdir, arch.String())
+	symbolsDir := image.symbolsDir.Join(ctx, os, image.installDirOnHost, arch.String())
 	symbolsFile := symbolsDir.Join(ctx, image.stem+".oat")
-	outputDir := image.dir.Join(ctx, os, image.installSubdir, arch.String())
+	outputDir := image.dir.Join(ctx, os, image.installDirOnHost, arch.String())
 	outputPath := outputDir.Join(ctx, image.stem+".oat")
 	oatLocation := dexpreopt.PathToLocation(outputPath, arch)
 	imagePath := outputPath.ReplaceExtension(ctx, "art")
@@ -753,7 +753,7 @@
 
 	cmd.Textf(`|| ( echo %s ; false )`, proptools.ShellEscape(failureMessage))
 
-	installDir := filepath.Join("/", image.installSubdir, arch.String())
+	installDir := filepath.Join("/", image.installDirOnHost, arch.String())
 
 	var vdexInstalls android.RuleBuilderInstalls
 	var unstrippedInstalls android.RuleBuilderInstalls
@@ -1036,7 +1036,7 @@
 				}
 				sfx := variant.name + suffix + "_" + variant.target.Arch.ArchType.String()
 				ctx.Strict("DEXPREOPT_IMAGE_VDEX_BUILT_INSTALLED_"+sfx, variant.vdexInstalls.String())
-				ctx.Strict("DEXPREOPT_IMAGE_"+sfx, variant.images.String())
+				ctx.Strict("DEXPREOPT_IMAGE_"+sfx, variant.imagePathOnHost.String())
 				ctx.Strict("DEXPREOPT_IMAGE_DEPS_"+sfx, strings.Join(variant.imagesDeps.Strings(), " "))
 				ctx.Strict("DEXPREOPT_IMAGE_BUILT_INSTALLED_"+sfx, variant.installs.String())
 				ctx.Strict("DEXPREOPT_IMAGE_UNSTRIPPED_BUILT_INSTALLED_"+sfx, variant.unstrippedInstalls.String())