Remove temp downloading NDK 25

[mszhanyi]

Description: Remove the hot fix (downing NDK25) introduced in #12350

Motivation and Context

• Why is this change required? What problem does it solve?
• If it fixes an open issue, please link to the issue here.

[edgchen1]

Please keep the pinning of the specific NDK version. You can remove the installation if you want. It's hard to detect if NDK version changes introduce issues otherwise.

[snnn]

I'm trying to update the VM images. I will still need a few days.

[mszhanyi]

Please keep the pinning of the specific NDK version. You can remove the installation if you want. It's hard to detect if NDK version changes introduce issues otherwise.

It might be necessary only for jobs on Mac whose image are not controlled by us.

[edgchen1]

Please keep the pinning of the specific NDK version. You can remove the installation if you want. It's hard to detect if NDK version changes introduce issues otherwise.

It might be necessary only for jobs on Mac whose image are not controlled by us.

I think we need to use a consistent version across different jobs. Explicitly specifying it (in this codebase) is helpful in my opinion, even if it's not necessary. I did spend a significant amount of time investigating an issue related to an NDK version change recently.