use vector<uint8_t> for byte[] in AIDL

In native world, byte stream is typically represented in uint8_t[]
or vector<uint8_t>. C++ backend already generates that way. This
change involves NDK backend.

Now NDK backend also uses vector<uint8_t> just like C++ backend.

Bug: 144957764
Test: atest CtsNdkBinderTestCases
Merged-In: I74bf803a3781c83c4102972f5df67312131bb879
Change-Id: I74bf803a3781c83c4102972f5df67312131bb879
(cherry picked from commit d9a228a937058ee0479d4dc180fb5f148c91a4fc)

Exempt-From-Owner-Approval: cp from master to avoid merge-conflict
diff --git a/cmds/statsd/src/StatsService.h b/cmds/statsd/src/StatsService.h
index 114c84f..460015c 100644
--- a/cmds/statsd/src/StatsService.h
+++ b/cmds/statsd/src/StatsService.h
@@ -94,13 +94,13 @@
      */
     virtual Status getData(int64_t key,
                            const int32_t callingUid,
-                           vector<int8_t>* output) override;
+                           vector<uint8_t>* output) override;
 
 
     /**
      * Binder call for clients to get metadata across all configs in statsd.
      */
-    virtual Status getMetadata(vector<int8_t>* output) override;
+    virtual Status getMetadata(vector<uint8_t>* output) override;
 
 
     /**
@@ -108,7 +108,7 @@
      * should requestData for this configuration.
      */
     virtual Status addConfiguration(int64_t key,
-                                    const vector<int8_t>& config,
+                                    const vector<uint8_t>& config,
                                     const int32_t callingUid) override;
 
     /**
@@ -318,7 +318,7 @@
     /**
      * Adds a configuration after checking permissions and obtaining UID from binder call.
      */
-    bool addConfigurationChecked(int uid, int64_t key, const vector<int8_t>& config);
+    bool addConfigurationChecked(int uid, int64_t key, const vector<uint8_t>& config);
 
     /**
      * Update a configuration.