Find out values for EN parameters and document where they come from

[haitrec]

Inside main/.../internal/EnFrameworkConstants.kt there are some constants set to values which have more or less been guessed. These constants are:

• MAX_EXPOSURE_INTERPOLATION_DURATION_SECONDS
• INTERPOLATION_ENABLED
• MIN_BUCKETIZED_DURATION_SECONDS

Somewhere in the EN framework documentation or the google code there should be hints to which values we should set these constants. We need to find out where to find this information, set the values correctly and document (in the code), where we got the values from.
The links under "Exposure Notifications" here should help. There are also some comments in our source code already pointing to google code, where the constants are used.
Even finding and documenting the correct value for one of these constants would be a great help!

(I marked this as a good first issue since it forces one to read through the EN documentation and the google code. However, if you did not look into that yet, it might take some time to get comfortable with.)