ANDROID: debug_symbols: Add android_debug_for_each_module

Allow vendors to obtain a list of modules loaded at given time. Vendor
modules are able to register on part of notifier chain
(register_module_notifer), but a vendor module would never see modules
which are loaded before the one which registers on the notifier chain.
The kernel doesn't offer load order control, so a hook is necessary to
iterate through currently loaded kernel modules.

Bug: 193552324
Change-Id: I3b01cc1b90f8c0c7c21a37992cc7d607316efc7b
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>