Fix floating toolbar menu item spacing.

We mistakenly changed floating_toolbar_menu_button_side_padding in
I309c729eb842d9388066bfb43eb18f33dbfe10b8 where in fact what we
wanted to do was to just change the mIconTextSpacing.
This cl fixes that.

Change-Id: I1b940eb12d2948f8c167c3f37ed0eba105b9f5ce
Fixes: 74032743
Test: built, observed visual look
Test: bit FrameworksCoreTests:android.widget.TextViewActivityTest
Test: bit CtsWidgetTestCases:android.widget.cts.TextViewTest