Do not initialize SSLSocketFactory too early

During Zygote initialization, the class may be preloaded. However we do
not want the default instances of SSLSocketFactory initialized, so move
those into a holder class so they are only initialized when used.

(cherry picked from commit 72017834153711733905dfcf4bfe7b802062692b)

Bug: 9984058
Change-Id: Ied901aa97dbbf0f7439f317d21d4b715b5705d96