This is the config how to block MAM config on Android Phones.
Go to https://endpoint.microsoft.com/
Endpoint security > Conditional Access
Create new Policy
Give it a name like No MAM – Android
Select Users or group or all.
Select Cloud apps Office 365.
Conditions -> Device platforms = Android
Filter for devices -> Rule syntax
device.operatingSystem -eq “AndroidForWork” -or device.operatingSystem -eq “AndroidEnterprise”
Grant = Block Access
Enable Policy.