smartlist: make floating action button smaller, cleaner

Change-Id: Ibf9a8419b5fd62b0f12d6b8fe39ddc9feb7a243a

ring-android/app/src/main/res/layout-w720dp-land/frag_smartlist.xml

@@ -71,15 +71,16 @@
             android:layout_marginBottom="@dimen/navigation_bottom_height" />
 
         <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
+            style="@style/Widget.AppTheme.MainActionButton"
             android:id="@+id/newconv_fab"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_alignWithParentIfMissing="false"
             android:layout_gravity="bottom|end"
-            android:layout_marginStart="@dimen/fab_margin"
-            android:layout_marginEnd="@dimen/fab_margin"
-            android:layout_marginTop="@dimen/fab_margin"
-            android:layout_marginBottom="92dp"
+            android:layout_marginStart="@dimen/fab_margin_mini"
+            android:layout_marginEnd="@dimen/fab_margin_mini"
+            android:layout_marginTop="@dimen/fab_margin_mini"
+            android:layout_marginBottom="72dp"
             android:elevation="6dp"
             android:text="@string/start_conversation"
             app:elevation="6dp"

ring-android/app/src/main/res/layout/frag_smartlist.xml

@@ -88,6 +88,7 @@ along with this program; if not, write to the Free Software
             tools:listitem="@layout/item_smartlist"/>
 
         <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
+            style="@style/Widget.AppTheme.MainActionButton"
             android:id="@+id/newconv_fab"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"

ring-android/app/src/main/res/values/styles.xml

@@ -84,6 +84,20 @@
 
     <style name="AppTheme.Fullscreen" parent="AppThemeBase.Fullscreen" />
 
+    <!-- Main action button -->
+    <style name="Widget.AppTheme.MainActionButton" parent="@style/Widget.MaterialComponents.ExtendedFloatingActionButton.Icon">
+        <item name="android:textAppearance">@style/TextAppearance.AppTheme.MainActionButton</item>
+        <item name="android:fontFamily">sans-serif</item>
+        <item name="android:textStyle">normal</item>
+        <item name="iconPadding">8dp</item>
+    </style>
+
+    <style name="TextAppearance.AppTheme.MainActionButton" parent="@style/TextAppearance.MaterialComponents.Button">
+        <item name="android:textAllCaps">false</item>
+        <item name="android:letterSpacing">0</item>
+        <item name="android:textSize">16sp</item>
+    </style>
+
     <!-- Transparent toolbar theme -->
     <style name="ActionBar.Transparent" parent="@android:style/Widget.DeviceDefault.Light.ActionBar.Solid.Inverse">
         <item name="android:background">@color/transparent_dark_grey</item>