Revert "Make r25.2.3 the default Android SDK"
This reverts commit a9e75da. `./mach build --android --dev` does not work with SDK 25.2.3. SDK 25.2.3 is still available for the `./mach package step`.
Revert "Make r25.2.3 the default Android SDK"
This reverts commit a9e75da. `./mach build --android --dev` does not work with SDK 25.2.3. SDK 25.2.3 is still available for the `./mach package step`.
