Use file glob for zipping classes*.dex files

Using a directory to zip the output of d8 and r8 was causing the
empty classes.dex.jar file in the output directory to get
zipped in.  Use a file glob instead so that it only picks up the
classes*.dex files even if classes.dex.jar already exists.

Test: m checkbuild
Change-Id: I1f3c1cbc23439fc52756aad027ab8cac10213d1d
diff --git a/java/dex.go b/java/dex.go
index 03316f6..ce0c18e 100644
--- a/java/dex.go
+++ b/java/dex.go
@@ -26,7 +26,7 @@
 	blueprint.RuleParams{
 		Command: `rm -rf "$outDir" && mkdir -p "$outDir" && ` +
 			`${config.D8Cmd} --output $outDir $d8Flags $in && ` +
-			`${config.SoongZipCmd} -o $outDir/classes.dex.jar -C $outDir -D $outDir && ` +
+			`${config.SoongZipCmd} -o $outDir/classes.dex.jar -C $outDir -f "$outDir/classes*.dex" && ` +
 			`${config.MergeZipsCmd} -D -stripFile "**/*.class" $out $outDir/classes.dex.jar $in`,
 		CommandDeps: []string{
 			"${config.D8Cmd}",
@@ -46,7 +46,7 @@
 			`-printmapping $outDict ` +
 			`$r8Flags && ` +
 			`touch "$outDict" && ` +
-			`${config.SoongZipCmd} -o $outDir/classes.dex.jar -C $outDir -D $outDir && ` +
+			`${config.SoongZipCmd} -o $outDir/classes.dex.jar -C $outDir -f "$outDir/classes*.dex" && ` +
 			`${config.MergeZipsCmd} -D -stripFile "**/*.class" $out $outDir/classes.dex.jar $in`,
 		CommandDeps: []string{
 			"${config.R8Cmd}",