Added keep-alive interval hint

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

@@ -447,6 +447,16 @@
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@id/tvInterval" />
 
+            <TextView
+                android:id="@+id/tvIntervalRemark"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/title_account_interval_hint"
+                android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                android:textStyle="italic"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toBottomOf="@id/etInterval" />
+
             <TextView
                 android:id="@+id/tvPrefix"
                 android:layout_width="wrap_content"
@@ -455,7 +465,7 @@
                 android:text="@string/title_account_prefix"
                 android:textAppearance="@style/TextAppearance.AppCompat.Small"
                 app:layout_constraintStart_toStartOf="parent"
-                app:layout_constraintTop_toBottomOf="@id/etInterval" />
+                app:layout_constraintTop_toBottomOf="@id/tvIntervalRemark" />
 
             <TextView
                 android:id="@+id/tvPrefixRemark"
@@ -770,7 +780,7 @@
             tvPrefix,tvPrefixRemark,etPrefix,cbNotify,tvNotifyPro,
             cbSynchronize,cbPrimary,
             cbBrowse,tvBrowseHint,
-            tvInterval,etInterval" />
+            tvInterval,etInterval,tvIntervalRemark" />
 
             <androidx.constraintlayout.widget.Group
                 android:id="@+id/grpFolders"

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

@@ -269,6 +269,7 @@
     <string name="title_account_linked">Linked account</string>
     <string name="title_account_name">Account name</string>
     <string name="title_account_name_hint">Used to differentiate folders</string>
+    <string name="title_account_interval_hint">Frequency of refreshing the connection for push messages or frequency of checking for new messages</string>
     <string name="title_account_prefix">Namespace prefix</string>
     <string name="title_account_prefix_hint">Used to simplify folder names</string>
     <string name="title_account_signature">Signature text</string>