Disable character creation finish button after click

This lead to crashes when user click this button twice in short time span.
Because when character save is run twice, fragment may be long gone
(detached from Activity) and when we try to use Fragment.context for Toast confirmation,
it's null.

Author: fmasa

app/src/main/java/cz/muni/fi/rpg/ui/characterCreation/CharacterCreationFragment.kt

@@ -1,5 +1,6 @@
 package cz.muni.fi.rpg.ui.characterCreation
 
+import android.content.Context
 import android.os.Bundle
 import android.view.View
 import android.widget.Toast
@@ -94,6 +95,9 @@ class CharacterCreationFragment(
                         return@setOnClickListener
                     }
 
+                    buttonNext.isEnabled = false
+                    buttonNextProgress.visibility = View.VISIBLE
+
                     saveCharacter(
                         info,
                         statsData,

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

@@ -60,6 +60,14 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="parent" />
 
+        <ProgressBar
+            android:id="@+id/buttonNextProgress"
+            android:visibility="gone"
+            app:layout_constraintEnd_toStartOf="@id/buttonNext"
+            app:layout_constraintTop_toTopOf="@id/buttonNext"
+            app:layout_constraintBottom_toBottomOf="@id/buttonNext"
+            android:layout_width="20dp"
+            android:layout_height="20dp"/>
         <androidx.appcompat.widget.AppCompatButton
             android:id="@+id/buttonNext"
             style="@style/Widget.MaterialComponents.Button.TextButton"