account wizard: handle state loss

...ain/java/cx/ring/account/RingAccountCreationFragment.java

...rc/main/java/cx/ring/account/RingLinkAccountFragment.java

...ava/cx/ring/tv/account/TVRingAccountCreationFragment.java

...in/java/cx/ring/tv/account/TVRingLinkAccountFragment.java

...src/main/java/cx/ring/account/AccountWizardPresenter.java

...in/java/cx/ring/account/RingAccountCreationPresenter.java

...rc/main/java/cx/ring/account/RingAccountCreationView.java

...c/main/java/cx/ring/account/RingLinkAccountPresenter.java

...nt/src/main/java/cx/ring/account/RingLinkAccountView.java