Remove R8-specific flags from soong config

Instead, move them to R8Wrapper. Having all of these R8-specific flags
in a single location, bundled within the R8 repo, is easier to maintain.
This should be a no-op for generated code.

Test: m + validate identical dex output
Change-Id: Ibdeecef8ca5d311d353dd623c73fab608ccd2681

java/config/config.go

@@ -96,10 +96,6 @@ func init() {
 	}, dexerJavaVmFlagsList...))
 	exportedVars.ExportStringListStaticVariable("R8Flags", append([]string{
 		"-JXmx2048M",
-		// Disable this optimization as it can impact weak reference semantics. See b/233432839.
-		"-JDcom.android.tools.r8.disableEnqueuerDeferredTracing=true",
-		// Disable class merging across different files to improve attribution. See b/242881914.
-		"-JDcom.android.tools.r8.enableSameFilePolicy=true",
 	}, dexerJavaVmFlagsList...))
 
 	exportedVars.ExportStringListStaticVariable("CommonJdkFlags", []string{