Fix Settings/Storage "Format USB drive" title string

Historically, this activity fragment had a "Format SD card for portable
storage" title string and the body text linked to
https://support.google.com/android/answer/12153449 which discusses
portable versus internal storage for SD cards.

For desktop Android, it is increasingly common to insert USB drives
instead of SD cards and the "portable versus internal" user decision is
less relevant here. This commit drops that link when not formatting an
SD card.

It also affects the title string, selecting between "Format SD card for
portable storage" and "Format USB drive". Some StorageWizardFoo activity
fragments' strings already made the SD card / USB drive distinction.
This commit makes it a little more consistent.

Bug: 373737145
Flag: EXEMPT minor fix
Test: manual
Change-Id: I3cf4b192e30566d5acb722b1d45cf14c5041706c