Rename APEX Namespace

Current APEX Namespace is named with APEX name itself, which also uses
.(dot) so linker configuration can keep the syntax safe.

For example, if there are APEX modules named 'A' and '', then
' =' phrase can be ambiguous from the
linker. To allow any additional linker syntax in the future, we should
avoid dot separator from the namespace name.

Bug: 148826508
Test: m -j passed
Test: boot succeeded from cuttlefish and walleye
Change-Id: I11b6da1b59b4ebf3016f1d783636c7e5d0f8309a
3 files changed