Azure Theme 7.0 dropdown fix for high contrast themes

[Jacqueline-ms]

Previous Behavior

High contrast light had style bug on selected and hover

High contrast dark had style bug on selected and hover

New Behavior

High contrast light

High contrast dark

Showing light and dark themes dropdown to prove no new bugs introduced.
Light:

[msft-fluent-ui-bot]

It looks like this change to the 7.0 branch may not have been submitted to master yet. Now that version 8 has released, all changes must be submitted to the master branch first (except in emergencies or if the change is irrelevant to version 8).

Please do one of the following:

• If you've already created a PR to master, add a link to it
• If the change is irrelevant to version 8, add a comment explaining why
• Otherwise, create a PR to master with this same change, and add a link to it

After that, you can dismiss this review and remove the "needs cherry-pick" label (or ask a team member to help do so).

Want to avoid this in the future? Include text like "Cherry-pick of ####" in the PR description (where #### is the real master PR number).

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 73b2cf2:

Sandbox	Source
Fluent UI Button	Configuration
codesandbox-react-template	Configuration

[github-advanced-security]

You have successfully added a new CodeQL configuration /language:javascript. As part of the setup process, we have scanned this repository and found no existing alerts. In the future, you will see all code scanning alerts on the repository Security tab.

[fabricteam]

🕵 FluentUI-v7 Open the Visual Regressions report to inspect the 2 screenshots

✅ There was 0 screenshots added, 2 screenshots removed, 1371 screenshots unchanged, 0 screenshots with different dimensions and 0 screenshots with visible difference.

unknown 2 screenshots

Image Name	Diff(in Pixels)	Image Type
PeoplePicker.Compact selected.default.chromium.png	0	Removed
PeoplePicker.Compact selected.suggestions.chromium.png	0	Removed

[fabricteam]

Perf Analysis

No significant results to display.

All results

Scenario	Render type	7.0 Ticks	PR Ticks	Iterations	Status
BaseButton	mount	1397	1432	5000
Breadcrumb	mount	44561	44781	5000
Checkbox	mount	2021	2068	5000
CheckboxBase	mount	1761	1747	5000
ChoiceGroup	mount	5586	5590	5000
ComboBox	mount	1443	1373	1000
CommandBar	mount	8602	8686	1000
ContextualMenu	mount	15105	14907	1000
DefaultButton	mount	1610	1593	5000
DetailsRow	mount	4417	4506	5000
DetailsRowFast	mount	4312	4511	5000
DetailsRowNoStyles	mount	4165	4322	5000
Dialog	mount	2758	2823	1000
DocumentCardTitle	mount	2438	2368	1000
Dropdown	mount	2970	3032	5000
FocusTrapZone	mount	2330	2344	5000
FocusZone	mount	2440	2396	5000
GroupedList	mount	1019	1161	2
GroupedListV2	mount	626	609	2
IconButton	mount	2275	2279	5000
Label	mount	822	797	5000
Layer	mount	2428	2431	5000
Link	mount	927	929	5000
MenuButton	mount	1938	1965	5000
MessageBar	mount	2661	2569	5000
Nav	mount	3764	3887	1000
OverflowSet	mount	1925	2047	5000
Panel	mount	1955	2066	1000
Persona	mount	1404	1473	1000
Pivot	mount	1905	1952	1000
PrimaryButton	mount	1811	1767	5000
Rating	mount	8602	8569	5000
SearchBox	mount	1771	1737	5000
Shimmer	mount	3003	3130	5000
Slider	mount	2104	2050	5000
SpinButton	mount	5563	5576	5000
Spinner	mount	926	911	5000
SplitButton	mount	3735	3775	5000
Stack	mount	1000	1017	5000
StackWithIntrinsicChildren	mount	2232	2191	5000
StackWithTextChildren	mount	5331	5275	5000
SwatchColorPicker	mount	11434	11174	5000
TagPicker	mount	3421	3445	5000
TeachingBubble	mount	52795	52865	5000
Text	mount	898	907	5000
TextField	mount	1892	1815	5000
Toggle	mount	1310	1288	5000
button	mount	614	608	5000

[Jacqueline-ms]

Cherry-picked into 8.0 via #27346

There is already a PR for the 8.0 branch in #27346

[size-auditor]

Asset size changes

Size Auditor did not detect a change in bundle size for any component!

Baseline commit: f21f21537d304b7747f6707d633c626e9f8dce75 (build)

[robtaft-ms]

This looks great, thank you again for taking care of this!