[Follow up to #15298] Do not prompt for storage access permission when share button is clicked on private tab

[srirambv]

Description

[Follow up to #15298] Do not prompt for storage access permission when share button is clicked on private tab

Steps to reproduce

1. Install 1.26.50
2. Visit a page in a private tab
3. Click on Shields and click on share button
4. Storage access prompt is shown to share stats

Actual result

Storage access prompt is shown on private tab to share stats when stats are only shown for normal tabs

Expected result

Maybe not show share button on private tabs? Unlike iOS Android doesn't show stats on private tabs

Issue reproduces how often

Easy

Version/Channel Information:

• Can you reproduce this issue with the current Play Store version? NA
• Can you reproduce this issue with the current Play Store Beta version? Yes
• Can you reproduce this issue with the current Play Store Nightly version? Yes

Device details

• Install type (ARM, x86): ARM
• Device type (Phone, Tablet, Phablet): All
• Android version: 10

Brave version

1.26.50

Website problems only

• Does the issue resolve itself when disabling Brave Shields? NA
• Does the issue resolve itself when disabling Brave Rewards? NA
• Is the issue reproducible on the latest version of Chrome? NA

Additional information

cc: @jumde @alexsafe @anthonypkeane