Fix server-triggered StackOverflowError in TS.43 phone number fetch

A deeply nested JSON response could trigger an unbounded recursion in
JSONTokener causing a StackOverflowError, which escaped the Exception
catch block and crashed the process. This changes catch (Exception) to
catch (Throwable) in Ts43PhoneNumberRetriever.java, and also adds catch
(Throwable) in Ts43PhoneNumberController.java to gracefully handle
unexpected Errors.

Bug: 517377722
Test: atest Ts43PhoneNumberRetrieverTest Ts43PhoneNumberControllerTest
Flag: EXEMPT BUGFIX

TAG=agy
CONV=96a2cb83-a901-4037-81da-7fa7df3a933f

(cherry picked from commit de8c73c03104687fdc52e14be9c1baf792c1bef8)
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:332287647dda3657dbc2a4d39b3e72b9090547c7
Merged-In: Ieef53664f3a25a2286c24d0b12c3132cfe94f562
Change-Id: Ieef53664f3a25a2286c24d0b12c3132cfe94f562
4 files changed