refactor: use Android's minTouchTargetSize

It replaces @dimen/touch_target with a Material standard attribute

It uses @dimen/mtrl_min_touch_target_size by default, which is the same `48dp` of before

Author: BrayanDSO

AnkiDroid/src/main/res/layout/browser_columns_selection_entry.xml

@@ -66,8 +66,8 @@
 
     <androidx.appcompat.widget.AppCompatImageButton
         android:id="@+id/button_toggle_column"
-        android:layout_width="@dimen/touch_target"
-        android:layout_height="@dimen/touch_target"
+        android:layout_width="?minTouchTargetSize"
+        android:layout_height="?minTouchTargetSize"
         style="@android:style/Widget.ActionButton"
         android:padding="8dp"
         tools:srcCompat="@drawable/ic_add"

AnkiDroid/src/main/res/layout/note_editor.xml

@@ -48,7 +48,7 @@
                     <Spinner
                         android:id="@+id/note_type_spinner"
                         android:layout_width="match_parent"
-                        android:layout_height="@dimen/touch_target"
+                        android:layout_height="?minTouchTargetSize"
                         />
                 </LinearLayout>
 

AnkiDroid/src/main/res/layout/reviewer2.xml

@@ -120,7 +120,7 @@
             android:id="@+id/buttons_area"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:minHeight="@dimen/touch_target"
+            android:minHeight="?minTouchTargetSize"
             android:layout_marginTop="2dp"
             android:layout_marginHorizontal="@dimen/reviewer_side_margin"
             >

AnkiDroid/src/main/res/layout/reviewer_answer_buttons.xml

@@ -65,7 +65,7 @@
                 android:id="@+id/flashcard_layout_ease1"
                 android:nextFocusRight="@id/flashcard_layout_ease2"
                 android:layout_width="0dip"
-                android:layout_height="@dimen/touch_target"
+                android:layout_height="?minTouchTargetSize"
                 android:layout_weight="1"
                 android:orientation="vertical"
                 android:theme="@style/AgainButton"
@@ -89,7 +89,7 @@
                 android:nextFocusRight="@id/flashcard_layout_ease3"
                 android:nextFocusLeft="@id/flashcard_layout_ease1"
                 android:layout_width="0dip"
-                android:layout_height="@dimen/touch_target"
+                android:layout_height="?minTouchTargetSize"
                 android:layout_weight="1"
                 android:orientation="vertical"
                 android:theme="@style/HardButton"
@@ -113,7 +113,7 @@
                 android:nextFocusRight="@id/flashcard_layout_ease4"
                 android:nextFocusLeft="@id/flashcard_layout_ease2"
                 android:layout_width="0dip"
-                android:layout_height="@dimen/touch_target"
+                android:layout_height="?minTouchTargetSize"
                 android:layout_weight="1"
                 android:orientation="vertical"
                 android:theme="@style/GoodButton"
@@ -136,7 +136,7 @@
                 android:id="@+id/flashcard_layout_ease4"
                 android:nextFocusLeft="@id/flashcard_layout_ease3"
                 android:layout_width="0dip"
-                android:layout_height="@dimen/touch_target"
+                android:layout_height="?minTouchTargetSize"
                 android:layout_weight="1"
                 android:orientation="vertical"
                 android:theme="@style/EasyButton"
@@ -157,7 +157,7 @@
         <FrameLayout
             android:id="@+id/flashcard_layout_flip"
             android:layout_width="match_parent"
-            android:layout_height="@dimen/touch_target"
+            android:layout_height="?minTouchTargetSize"
             android:orientation="vertical"
             android:focusable="true"
             android:background="?attr/hardButtonRef"

AnkiDroid/src/main/res/layout/sync_progress_layout.xml

@@ -8,8 +8,8 @@
 
     <androidx.appcompat.widget.AppCompatImageButton
         android:id="@+id/button"
-        android:layout_width="@dimen/touch_target"
-        android:layout_height="@dimen/touch_target"
+        android:layout_width="?minTouchTargetSize"
+        android:layout_height="?minTouchTargetSize"
         app:srcCompat="@drawable/ic_sync"
         style="@android:style/Widget.ActionButton"
         android:tooltipText="@string/button_sync"

AnkiDroid/src/main/res/values/dimens.xml

@@ -2,7 +2,6 @@
 <resources xmlns:tools="http://schemas.android.com/tools" tools:ignore="UnusedResources,DuplicateCrowdInStrings">
     <!-- Material UI side margin: http://web.archive.org/web/20180105203433if_/https://material.io/guidelines/layout/metrics-keylines.html#metrics-keylines-keylines-spacing -->
     <dimen name="side_margin">16dp</dimen>
-    <dimen name="touch_target">48dp</dimen>
     <dimen name="default_width">56dp</dimen>
     <dimen name="keyline_1">16dp</dimen>
     <dimen name="study_options_padding">8dp</dimen>