Migrate to androidx

Change-Id: I88bbcdfa4a8dd0f0e159dbfced94f640889688de
Signed-off-by: Aayush Gupta <aayushgupta219@gmail.com>
diff --git a/Android.bp b/Android.bp
index a25be55..bdecc41 100644
--- a/Android.bp
+++ b/Android.bp
@@ -18,10 +18,13 @@
 
 android_library {
     name: "colorpicker",
-    sdk_version: "15",
+    sdk_version: "current",
     srcs: [
         "src/**/*.java",
         "src/**/*.logtags",
     ],
+    static_libs: [
+        "androidx.fragment_fragment",
+    ],
     resource_dirs: ["res"],
 }
diff --git a/src/com/android/colorpicker/ColorPickerDialog.java b/src/com/android/colorpicker/ColorPickerDialog.java
index 0d24b49..03131e2 100644
--- a/src/com/android/colorpicker/ColorPickerDialog.java
+++ b/src/com/android/colorpicker/ColorPickerDialog.java
@@ -19,12 +19,13 @@
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.Dialog;
-import android.app.DialogFragment;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.ProgressBar;
 
+import androidx.fragment.app.DialogFragment;
+
 import com.android.colorpicker.ColorPickerSwatch.OnColorSelectedListener;
 
 /**