Removal of text/util spi classes and references

This commit contains changes to docs and code.

Reasoning:

The changes made in Android to delegate through to ICU for
various I18N concerns make it unlikely that Android could
support the SPI code without substantial testing.

Explicitly removing the code and docs removes the
pretence / confusion over Android support for pluggable
locale data. It has definite code-size impact and will have
a slight runtime performance improvement.

Changes:

The docs previously referenced SPI classes that are not
public on Android. These references and associated
conditional text have been removed. Some references to
methods returning at least Locale.US have also been
removed because Android provides a larger set.

Code related to calls to the LocaleServiceProviderPool
has been removed or commented. The SPI classes and internal
support classes have been deleted.

Some additional "Android-changed" markers have been made
to highlight Android changes associated with the use of ICU
and/or preexisting removal of the SPI.

Bug: 31851669
Test: Ran CtsLibcoreTestCase and make checkbuild
Change-Id: I262b33f2c88d88dbb0c2f1d2b116952dc4e046e3

0 files changed, 0 insertions, 0 deletions