Here is my java class.
public class MyPrefrences extends PreferenceActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.preferences);
}
}
in my project i used preferences.xml
<PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory
        android:title="@string/steps_settings_title">
    <ListPreference
            android:key="sensitivity"
            android:title="@string/setting"
            android:summary="@string/setting_details"
            android:entries="@array/preference"
            android:entryValues="@array/preference_values"
            android:dialogTitle="@string/setting_title"
            android:defaultValue="30" />
    <ListPreference
            android:key="operation_level"
            android:title="@string/operation_level_setting"
            android:summary="@string/operation_level_setting_details"
            android:entries="@array/operation_level_preference"
            android:entryValues="@array/operation_level_preference_values"
            android:dialogTitle="@string/operation_level_setting_title"
            android:defaultValue="30" />
    <ListPreference
            android:key="units"
            android:title="@string/units_setting"
            android:summary="@string/units_setting_details"
            android:entries="@array/units_preference"
            android:entryValues="@array/units_preference_values"
            android:dialogTitle="@string/units_setting_title"
            android:defaultValue="imperial" />
    <com.example.myapp.preferences.StepLengthPreference
            android:key="length"
            android:title="@string/length_setting"
            android:summary="@string/length_setting_details"
            android:dialogTitle="@string/length_setting_title"
            android:defaultValue="20" />
    <com.example.myapp.preferences.BodyWeightPreference
            android:key="body_weight"
            android:title="@string/weight_setting"
            android:summary="@string/weight_setting_details"
            android:dialogTitle="@string/weight_setting_title"
            android:defaultValue="50" />
    <ListPreference
            android:key="exercise_type"
            android:title="@string/type_setting"
            android:summary="@string/type_setting_details"
            android:entries="@array/type_preference"
            android:entryValues="@array/type_preference_values"
            android:dialogTitle="@string/type_setting_title"
            android:defaultValue="running" />
    <ListPreference
            android:key="maintain"
            android:title="@string/maintain_setting"
            android:summary="@string/maintain_setting_details"
            android:entries="@array/maintain_preference"
            android:entryValues="@array/maintain_preference_values"
            android:dialogTitle="@string/maintain_setting_title"
            android:defaultValue="none" />
</PreferenceCategory>
</PreferenceScreen>
how can i fix this according to new google security policies. Your app(s) have an unsafe implementation where PreferenceActivity classes may be susceptible to Fragment Injection. set exported=false for the affected PreferenceActivity in your Manifest Incorrect implementation of isValidFragment How can they may fixed?
                        
This code works perfectly for me: