Move the Once cache for dexpreopt.GlobalConfig into the dexpreopt
package.

Preparation for a future CL that will need to get the make-written
GlobalConfig from within dexpreopt.

Also rename the Load*Config functions to Parse*Config, since they don't
actually load the config files anymore.

Bug: 145934348
Test: m
Change-Id: I71df11c1e042ca8135d273a7263e9539ea3cd68f
diff --git a/java/dexpreopt.go b/java/dexpreopt.go
index 0734b3f..0fd1f28 100644
--- a/java/dexpreopt.go
+++ b/java/dexpreopt.go
@@ -59,7 +59,7 @@
 }
 
 func (d *dexpreopter) dexpreoptDisabled(ctx android.ModuleContext) bool {
-	global := dexpreoptGlobalConfig(ctx)
+	global := dexpreopt.GetGlobalConfig(ctx)
 
 	if global.DisablePreopt {
 		return true
@@ -96,7 +96,7 @@
 }
 
 func odexOnSystemOther(ctx android.ModuleContext, installPath android.InstallPath) bool {
-	return dexpreopt.OdexOnSystemOtherByName(ctx.ModuleName(), android.InstallPathToOnDevicePath(ctx, installPath), dexpreoptGlobalConfig(ctx))
+	return dexpreopt.OdexOnSystemOtherByName(ctx.ModuleName(), android.InstallPathToOnDevicePath(ctx, installPath), dexpreopt.GetGlobalConfig(ctx))
 }
 
 func (d *dexpreopter) dexpreopt(ctx android.ModuleContext, dexJarFile android.ModuleOutPath) android.ModuleOutPath {
@@ -105,7 +105,7 @@
 	}
 
 	globalSoong := dexpreopt.GetGlobalSoongConfig(ctx)
-	global := dexpreoptGlobalConfig(ctx)
+	global := dexpreopt.GetGlobalConfig(ctx)
 	bootImage := defaultBootImageConfig(ctx)
 	if global.UseApexImage {
 		bootImage = frameworkJZBootImageConfig(ctx)