Preopt: Do not strip non-image boot class path jars.

Test: Pixel 2 XL boots.
Bug: 119868597
Change-Id: I7bd3b7655aecf1a8c26dd8d4d18d3eec685ece88
diff --git a/dexpreopt/config.go b/dexpreopt/config.go
index 6b5c40d..503af7e 100644
--- a/dexpreopt/config.go
+++ b/dexpreopt/config.go
@@ -36,6 +36,7 @@
 	PreoptBootClassPathDexLocations []string // virtual locations of boot class path files
 
 	BootJars         []string // modules for jars that form the boot class path
+	PreoptBootJars   []string // modules for jars that form the boot image
 	SystemServerJars []string // jars that form the system server
 	SystemServerApps []string // apps that are loaded into system server
 	SpeedApps        []string // apps that should be speed optimized