16KB: Fix failing tests for AOSP targets

UiAutomator is case sensitive. On AOSP builds, the "Erase all data"
string is displayed in all caps in the dialog box on trying to erase all
data and switch to ext4 mode. This is a workaround fix for the issue.

Bug: 390535191
Flag: EXEMPT bugfix
Test: Enable16kbTest on AOSP Pixel 8 targets
Change-Id: I119fe076eb3eb037a23f07af77b9ad4935cb4064