Fix Proguard configuration output from R8 invocation

The output when using `--pg-conf-output` seems to be flaky. In the
meantime, use `-printconfiguration` to generate full config summaries
for each R8 invocation.

Bug: 281081834
Test: m && \
      find $ANDROID_BUILD_TOP/out -name proguard_configuration -empty
Change-Id: I0c8c36212e338b50505184076f4c470a5d3d9b94

java/dex.go

@@ -140,7 +140,7 @@ var r8, r8RE = pctx.MultiCommandRemoteStaticRules("r8",
 			`$r8Template${config.R8Cmd} ${config.R8Flags} -injars $tmpJar --output $outDir ` +
 			`--no-data-resources ` +
 			`-printmapping ${outDict} ` +
-			`--pg-conf-output ${outConfig} ` +
+			`-printconfiguration ${outConfig} ` +
 			`-printusage ${outUsage} ` +
 			`--deps-file ${out}.d ` +
 			`$r8Flags && ` +