PasswordInput: Don't let show/hide button stretch password input's height

The default value for `alignItems` is 'stretch':
  https://reactnative.dev/docs/0.68/flexbox#align-items

Author: chrisbobbe

src/common/PasswordInput.js

@@ -11,7 +11,6 @@ import Touchable from './Touchable';
 
 const styles = createStyleSheet({
   showPasswordButton: {
-    justifyContent: 'center',
     marginLeft: 8,
   },
   showPasswordButtonIcon: {
@@ -23,6 +22,7 @@ const styles = createStyleSheet({
   },
   passwordInputView: {
     flexDirection: 'row',
+    alignItems: 'center',
   },
 });