Enables Speedreader on Android for all users on nightly and beta channels

[SergeyZhukovsky]

Resolves #564

[kjozwiak]

Merging into main so QA can run through the above on staging before uplifting/merging #566 into production.

[kjozwiak]

Android verifications on Nightly

Went through the STR/Cases mentioned via brave/brave-core#10408 (comment) and ensured that Brave was using https://variations.bravesoftware.com/seed which is the staging URL.

Used the STR/Cases outlined via #564 (comment) as a guideline for the test cases that I ran through below.

Pixel 6 running Android 13 Test Cases using Nightly

SpeedreaderAndroidStudy:Enabled

Verification PASSED on Pixel 6 running Android 13 using the following build(s):

Brave | 1.52.5 Chromium: 112.0.5615.49 (Official Build) canary (32-bit)
--- | ---
Revision | bd2a7bcb881c11e8cfe3078709382934e3916914-refs/branch-heads/5615@{#936}
OS | Android 13; Build/TQ2A.230305.008.E1

• launched 1.52.5 Chromium: 112.0.5615.49 and ensured that SpeedreaderAndroidStudy wasn't visible under brave://version
• restarted the browser and ensured that SpeedreaderAndroidStudy:Enabled via brave://version
• visited several articles under cnn.com & nyt.com and ensured that the articles were not being loaded in reader mode
• ensured that Enable Speedreader is disabled by default via Settings -> Appearance
• enabled Enable Speedreader via Settings -> Appearance
• visited several articles and ensured that they were loading in reader mode due to Speedreader being enabled
• ensured that disabling Speedreader worked without any issues and articles stopped loading in reader mode
• ensured that restarting the browser several times didn't change the current state (Disabled/Enabled Speedreader)
• ensured that View original within an article that's in Reader Mode loads the original website without any issues

Example	Example	Example	Example	Example	Example	Example

---

Pixel 6 running Android 13 Test Cases using BETA

SpeedreaderAndroidStudy:Enabled

Verification PASSED on Pixel 6 running Android 13 using the following build(s):

Brave | 1.51.71 Chromium: 112.0.5615.39 (Official Build) beta (32-bit)
--- | ---
Revision | a0e7b9718a92bcd1cf33b7c95316caff3fc20714-refs/branch-heads/5615@{#753}
OS | Android 13; Build/TQ2A.230305.008.E1

• launched 1.51.71 Chromium: 112.0.5615.39 and ensured that SpeedreaderAndroidStudy wasn't visible under brave://version
• restarted the browser and ensured that SpeedreaderAndroidStudy:Enabled via brave://version
• visited several articles under cnn.com & nyt.com and ensured that the articles were not being loaded in reader mode
• ensured that Enable Speedreader is disabled by default via Settings -> Appearance
• enabled Enable Speedreader via Settings -> Appearance
• visited several articles and ensured that they were loading in reader mode due to Speedreader being enabled
• ensured that disabling Speedreader worked without any issues and articles stopped loading in reader mode
• ensured that restarting the browser several times didn't change the current state (Disabled/Enabled Speedreader)
• ensured that View original within an article that's in Reader Mode loads the original website without any issues

Example	Example	Example	Example	Example	Example	Example

---

Pixel 6 running Android 13 Test Cases using Release

SpeedreaderAndroidStudy not being used/visible under brave://version

Verification PASSED on Pixel 6 running Android 13 using the following build(s):

Brave | 1.49.132 Chromium: 111.0.5563.147 (Official Build) (32-bit)
--- | ---
Revision | 029fd65a4dd711d1078468ed2206999cec86066b-refs/branch-heads/5563@{#1239}
OS | Android 13; Build/TQ2A.230305.008.E1

• launched 1.49.132 Chromium: 111.0.5563.147 and ensured that SpeedreaderAndroidStudy wasn't visible under brave://version
• restarted the browser and ensured that SpeedreaderAndroidStudy:Enabled isn't visible via brave://version
• ensure that Speedreader toggle isn't available via Settings -> Appearance

Example	Example