feat(YouTube Music - Change start page): Add more start pages

[ILoveOpenSourceApplications]

Hopefully close #1905 and close #2641.

[ILoveOpenSourceApplications]

For Liked Music: "browseId\":\"VLLM\". URL: https://music.youtube.com/playlist?list=LM.
For Episodes for Later: "browseId\":\"VLSE\",\. URL: https://music.youtube.com/playlist?list=SE.

I believe simply adding that value won't be enough for these two. If so, what changes would be needed?

Simply adding them would be enough.

Also, Samples isn't available on web, so will it be similar to how it's achieved in YouTube, as in adding com.google.android.app.youtube.music.action.open.samples? Same for search as well?

[inotia00]

Due to the limitations of the app structure, the Change start page patch was implemented in different ways on YouTube and YouTube Music.

In the case of YouTube, Intent for shortcut is public, so we can use Intent declared in AndroidManifest:

com.google.android.youtube.action.open.search
com.google.android.youtube.action.open.shorts

In the case of YouTube Music, the Intent for shortcut is private, so Intent is generated by the app's internal code.

According to the internal code, the available shortcuts are as follows:

QUICK_ACTION_TYPE_UNKNOWN
QUICK_ACTION_TYPE_SEARCH
QUICK_ACTION_TYPE_MY_MIX
QUICK_ACTION_TYPE_OFFLINE_MIXTAPE
QUICK_ACTION_TYPE_SHUFFLE_DOWNLOADS
QUICK_ACTION_TYPE_PODCASTS

Using shortcut seems to require a specific parameter (Base64) from the server side, as well as the Enum#ordinal().

(The parameter is encoded, but it was probably originally proto buffer)

The way to get this parameter is unknown.