Allow ro. properties to have arbitrary lengths

Android now allows ro. properties to have arbitrary lengths.  Two
changes need to happen to support this:

1) The length check in setprop.c before attempting to set a property
   needs to be removed for ro. properties
2) __system_property_read_callback() must be used in place of
   __system_property_get() in getprop.c as only the former is capable
   of reading properties with size > 92 characters.

Bug: 23102347
Bug: 34954705
Change-Id: Ib8565a3e6d987dd5e6a5fe790e804ecf8ad1e020
2 files changed