Delay SSLSocketImpl instantiation until needed DO NOT MERGE

Class preloading will create an instance of objects if they are in
static fields, so put the ones we don't want instantiated into a holder
class that is not preloaded.

(cherry picked from commit da5b7116b58795b169961cbd63c2b21bac741d9a)

Bug: 9984058
Change-Id: Ifbf7b7a3668f19ca21fa66a486ae557086a195b5
Merge tag 'android-4.3_r3.1' of https://android.googlesource.com/platform/libcore into jb3

Android 4.3 Release 3.1