Add support for remote-execution / caching of turbine actions

Test: Ran a sample turbine action with:
RBE_TURBINE_EXEC_STRATEGY="remote" RBE_TURBINE="true" ... use_rbe m out/soong/.intermediates/external/protobuf/libprotobuf-java-micro/android_common/turbine/libprotobuf-java-micro.jar
and checked in reproxy_log.txt that remote-metadata had status SUCCESS.

Bug: b/156765475
Change-Id: I85c334e6998c6dd2a68460b3580d50fffd900e6f
diff --git a/remoteexec/remoteexec.go b/remoteexec/remoteexec.go
index 99e29dc..2b513b2 100644
--- a/remoteexec/remoteexec.go
+++ b/remoteexec/remoteexec.go
@@ -75,6 +75,9 @@
 	// OutputFiles is a list of output file paths or ninja variables as placeholders for rule
 	// outputs.
 	OutputFiles []string
+	// OutputDirectories is a list of output directory paths or ninja variables as placeholders
+	// for rule outputs.
+	OutputDirectories []string
 	// ToolchainInputs is a list of paths or ninja variables pointing to the location of
 	// toolchain binaries used by the rule.
 	ToolchainInputs []string
@@ -151,6 +154,10 @@
 		args += " --output_files=" + strings.Join(r.OutputFiles, ",")
 	}
 
+	if len(r.OutputDirectories) > 0 {
+		args += " --output_directories=" + strings.Join(r.OutputDirectories, ",")
+	}
+
 	if len(r.ToolchainInputs) > 0 {
 		args += " --toolchain_inputs=" + strings.Join(r.ToolchainInputs, ",")
 	}
@@ -159,7 +166,9 @@
 }
 
 // StaticRules returns a pair of rules based on the given RuleParams, where the first rule is a
-// locally executable rule and the second rule is a remotely executable rule.
+// locally executable rule and the second rule is a remotely executable rule. commonArgs are args
+// used for both the local and remotely executable rules. reArgs are used only for remote
+// execution.
 func StaticRules(ctx android.PackageContext, name string, ruleParams blueprint.RuleParams, reParams *REParams, commonArgs []string, reArgs []string) (blueprint.Rule, blueprint.Rule) {
 	ruleParamsRE := ruleParams
 	ruleParams.Command = strings.ReplaceAll(ruleParams.Command, "$reTemplate", "")