test(sdk): replace flaky timeout with localStorage polling

[overbalance]

What problem is this solving?

Fixes flaky test should namespace the storage for each instance based on appID that was failing intermittently on CI due to a race condition.

Short description of changes

• Added waitForLocalStorageKeys polling helper in the isolated instances test suite
• Replaced 2ms fixed timeouts with polling that waits for remote config keys to be set
• Updated 3 tests that were susceptible to the same race condition

[github-actions]

Chrome DevTools Protocol Tracing (Script: 102.47ms, Heap: 13.92MB)

	Number of Requests	Size of Requests	Script Duration	Task Duration	Heap Used Size
Requests	+3 requests	+29.73 KB
Page Loaded			+15.06 ms	+10.50 ms	+0.94 MB
Generate 100 fetch requests			+15.72 ms	+73.88 ms	+2.00 MB
Generate 100 XHR requests			+37.56 ms	+115.86 ms	+2.39 MB
Click 100 buttons and generate 100 logs			+23.60 ms	+28.70 ms	+2.98 MB
Throw a 100 exceptions			+3.35 ms	+16.49 ms	+2.47 MB
End Session			+7.18 ms	+14.86 ms	+3.15 MB
Total	+3 requests	+29.73 KB	+102.47 ms	+260.30 ms	+13.92 MB

Lighthouse (Script Eval: 46.00ms)

	Difference	Description
Total Blocking Time	0 ms	Difference in Total Blocking Time: Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds. Learn more about the Total Blocking Time metric.
Main Thread Time	+60.97 ms	Difference in Main Thread Time: Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work
Script Evaluation Time	+46.00 ms	Difference in Script Evaluation Time: Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.

Platform Tests (vite-7 gzip: 47.60KB)

vite-7 Platform Tests

	Total Uncompressed Size	Total Gzip Size
vite-7 - esnext	+163.90 KB	+47.60 KB
vite-7 - es2015	+170.67 KB	+49.25 KB

vite-otel-latest Platform Tests

	Total Uncompressed Size	Total Gzip Size
vite-otel-latest - esnext	+162.97 KB	+49.11 KB
vite-otel-latest - es2015	+169.67 KB	+50.70 KB

webpack-5 Platform Tests

	Total Uncompressed Size	Total Gzip Size
webpack-5 - esnext	+120.06 KB	+42.58 KB
webpack-5 - es2015	+121.18 KB	+44.09 KB