-Improved player queue stability by using more aggressive synchronization policy.

-Added sync buttons on live streams to allow seeking to live edge.
-Added custom cache key for extractor sources to allow more persistent reuse.
-Refactored player data source factories into own class and separating live and non-live data sources.

app/src/main/res/layout-land/activity_player_queue_control.xml

@@ -296,5 +296,15 @@
             android:textColor="?attr/colorAccent"
             tools:ignore="HardcodedText"
             tools:text="1:23:49"/>
+
+        <TextView
+            android:id="@+id/live_sync"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent"
+            android:gravity="center"
+            android:text="@string/live_sync"
+            android:textColor="?attr/colorAccent"
+            android:background="?attr/selectableItemBackground"
+            android:visibility="gone"/>
     </LinearLayout>
 </RelativeLayout>

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

@@ -397,6 +397,17 @@
                     android:textColor="@android:color/white"
                     tools:ignore="HardcodedText"
                     tools:text="1:23:49"/>
+
+                <TextView
+                    android:id="@+id/playbackLiveSync"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:gravity="center_vertical"
+                    android:text="@string/live_sync"
+                    android:textColor="@android:color/white"
+                    android:visibility="gone"
+                    android:background="?attr/selectableItemBackground"
+                    tools:ignore="HardcodedText,RtlHardcoded,RtlSymmetry" />
             </LinearLayout>
         </RelativeLayout>
 

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

@@ -146,6 +146,16 @@
             android:textColor="?attr/colorAccent"
             tools:ignore="HardcodedText"
             tools:text="1:23:49"/>
+
+        <TextView
+            android:id="@+id/live_sync"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent"
+            android:gravity="center"
+            android:text="@string/live_sync"
+            android:textColor="?attr/colorAccent"
+            android:background="?attr/selectableItemBackground"
+            android:visibility="gone"/>
     </LinearLayout>
 
     <RelativeLayout

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

@@ -190,6 +190,17 @@
                 android:textColor="@android:color/white"
                 tools:ignore="HardcodedText,RtlHardcoded,RtlSymmetry"
                 tools:text="1:23:49"/>
+
+            <TextView
+                android:id="@+id/playbackLiveSync"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:gravity="center_vertical"
+                android:text="@string/live_sync"
+                android:textColor="@android:color/white"
+                android:visibility="gone"
+                android:background="?attr/selectableItemBackground"
+                tools:ignore="HardcodedText,RtlHardcoded,RtlSymmetry" />
         </LinearLayout>
     </RelativeLayout>
 

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

@@ -413,6 +413,8 @@
     <string name="normal_caption_font_size">Normal Font</string>
     <string name="larger_caption_font_size">Larger Font</string>
 
+    <string name="live_sync">SYNC</string>
+
     <!-- Debug Settings -->
     <string name="enable_leak_canary_title">Enable LeakCanary</string>
     <string name="enable_leak_canary_summary">Memory leak monitoring may cause app to become unresponsive when heap dumping</string>