feat(UI): rounded editText inputs

app/src/main/res/drawable/rounded_edittext.xml

+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <solid android:color="#FFFFFF"/> <!-- Background color -->
+    <corners android:radius="16dp"/> <!-- Rounded corners -->
+    <stroke
+        android:width="2dp"
+        android:color="#000000"/> <!-- Border color and width -->
+</shape>
\ No newline at end of file

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

@@ -21,6 +21,7 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="@string/first_name_label"
+
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintHorizontal_bias="0.046"
@@ -77,6 +78,8 @@
             android:hint="@string/first_name_placeholder"
             android:inputType="text"
             android:minHeight="48dp"
+            android:background="@drawable/rounded_edittext"
+            android:gravity="center"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintHorizontal_bias="0.0"
@@ -95,6 +98,8 @@
             android:hint="@string/last_name_placeholder"
             android:inputType="text"
             android:minHeight="48dp"
+            android:background="@drawable/rounded_edittext"
+            android:gravity="center"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintHorizontal_bias="0.0"
@@ -113,6 +118,8 @@
             android:hint="@string/birth_date_placeholder"
             android:inputType="date"
             android:minHeight="48dp"
+            android:background="@drawable/rounded_edittext"
+            android:gravity="center"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintHorizontal_bias="0.039"
@@ -131,6 +138,8 @@
             android:hint="@string/birth_city_placeholder"
             android:inputType="text"
             android:minHeight="48dp"
+            android:background="@drawable/rounded_edittext"
+            android:gravity="center"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintHorizontal_bias="0.109"
@@ -145,6 +154,7 @@
             android:layout_marginTop="27dp"
             android:onClick="validateAction"
             android:text="@string/validate"
+            android:background="#000000"
             app:cornerRadius="0dp"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"