Match native SDKs text for simulated store purchase alert

[ajpallares]

• Aligns the browser simulated store purchase alert text with the native iOS and Android SDKs.
• Related: Match iOS casing for Test Store purchase button labels purchases-android#3314
• Unit tests updated.

Changes

The browser simulated store alert used different casing and a shorter title compared to the native SDKs:

	Before (RN)	After (matches native)
Title	"Test Purchase"	"Test Store Purchase"
Success button	"Test Valid Purchase"	"Test valid purchase"
Failure button	"Test Failed Purchase"	"Test failed purchase"

Made with Cursor

[tonidero]

Looks good! Thanks for consolidating these! 🙏