Bump version numbers before release of v0.1.9

Including a protocol version bump due to new command for accelerometer latency
added in #108

Author: Mark Koudritsky

android/WALT/app/build.gradle

@@ -9,8 +9,8 @@ model {
             applicationId "org.chromium.latency.walt"
             minSdkVersion.apiLevel 17
             targetSdkVersion.apiLevel 23
-            versionCode 8
-            versionName "0.1.7"
+            versionCode 9
+            versionName "0.1.9"
         }
         ndk {
             moduleName "sync_clock_jni"

android/WALT/app/src/main/java/org/chromium/latency/walt/WaltDevice.java

@@ -31,7 +31,7 @@ public class WaltDevice implements WaltConnection.ConnectionStateListener {
 
     private static final int DEFAULT_DRIFT_LIMIT_US = 1500;
     private static final String TAG = "WaltDevice";
-    public static final String PROTOCOL_VERSION = "5";
+    public static final String PROTOCOL_VERSION = "6";
 
     // Teensy side commands. Each command is a single char
     // Based on #defines section in walt.ino