Add commit id into About screen

app/build.gradle

@@ -15,6 +15,19 @@ tasks.withType(Test) {
     systemProperty "GB_LOGFILES_DIR", Files.createTempDirectory("gblog").toString()
 }
 
+def getGitHashShort = { ->
+    try {
+        def stdout = new ByteArrayOutputStream()
+        exec {
+            commandLine 'git', 'rev-parse', '--short', 'HEAD'
+            standardOutput = stdout
+        }
+        return stdout.toString().trim()
+    } catch (ignored){
+        return null
+    }
+}
+
 android {
     compileOptions {
         // for KitKat
@@ -35,6 +48,7 @@ android {
         versionCode 208
         vectorDrawables.useSupportLibrary = true
         multiDexEnabled true
+        buildConfigField "String", "GIT_HASH_SHORT", "\"${getGitHashShort()}\""
     }
     buildTypes {
         release {

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AboutActivity.java

@@ -31,8 +31,11 @@ public class AboutActivity extends AbstractGBActivity {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_about);
         TextView about_version = findViewById(R.id.about_version);
+        TextView about_hash = findViewById(R.id.about_hash);
         String versionName = BuildConfig.VERSION_NAME;
+        String versionHASH = BuildConfig.GIT_HASH_SHORT;
         about_version.setText(String.format(getString(R.string.about_version), versionName));
+        about_hash.setText(String.format(getString(R.string.about_hash), versionHASH));
 
         TextView link1 = findViewById(R.id.links1);
         link1.setMovementMethod(LinkMovementMethod.getInstance());

app/src/main/res/layout/activity_about.xml

@@ -53,6 +53,12 @@
                     android:id="@+id/about_version"
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content" />
+
+                <TextView
+                    android:id="@+id/about_hash"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content" />
+
             </LinearLayout>
 
             <TextView

app/src/main/res/values/strings.xml

@@ -1079,6 +1079,7 @@
     <string name="fdroid_url" translatable="false">F-Droid: <a href="https://f-droid.org/packages/nodomain.freeyourgadget.gadgetbridge/">https://f-droid.org/packages/nodomain.freeyourgadget.gadgetbridge/</a></string>
     <string name="about_title">About</string>
     <string name="about_version">Version %s</string>
+    <string name="about_hash">Commit %s</string>
     <string name="about_activity_title">About Gadgetbridge</string>
     <string name="gpx_receiver_activity_title">GPX Receiver Gadgetbridge</string>
     <string name="gpx_receiver_files_received">GPX file(s) received:</string>