soong: upgrade Android platform to clang-r370808

-Wc99-designators warns for the use of nested and array initializers in
C++20 code. Many internal projects have pushed back against this
warning.

Disables:
- -Wimplicit-int-float-conversion
- -Wpointer-compare
- -Wxor-used-as-pow
- -Wfinal-dtor-non-final-class
- -Wreorder-init-list

For projects under external/, vendor/, etc, but only if they use
Android.bp (not Android.mk) and -Wreorder-init-list may be re-enabled by
-Wall if set locally.

-Wno-incomplete-setjmp-declaration is needed for NDK stubs that get
generated (functions without full definitions of their parameters).

Sets
- -Wno-error=implicit-int-float-conversion
- -Wno-error=reorder-init-list
for all projects in order to unblock landing the compiler upgrade due to
internal projects not being able to disable or fix these before the
upgrade.

Bug: 139945549
Test: build (aosp_crosshatch, crosshatch, aosp_x86_64-eng,
  walleye), boot internal devices, bionic + RS atests, kernel builds.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Change-Id: I18e3c0eb657fd59824526f36c6dd57bdcf0526ba