Installer step 4: remove obsolete 'bit' radio buttons

Installer step 4 (Select JVM) has 'Installation Type' and radio buttons for 64 and 32 bit Java developer kits. This is now obsolete and should be removed:

• There is no 32-bit supported OS X-JDK combination.
• The radio buttons don't work for Linux-based or Windows OS for which there is supported 32/64 bit supported OS-JDK combinations.