This updates the Cargo submodule a bit but is otherwise pretty routine.

Apparently the https urls are broken due to some certificate validation
whatnots, and so far the least intrusive solution I've found is to just disable
that.

Prepare the 1.22.0 beta

This updates the Cargo submodule a bit but is otherwise pretty routine.

[beta] Make Solaris builder compatible with Solaris 10

Backport of #45255.

…nKind.

…_order().

[beta] Backport incremental compilation fix

This is a backport of #45176 along with a bump of the beta number so we can hopefully update the bootstrap compiler in #45285

Unfortunately, #45255 does not quite cut it,
so use a different approach to have Solaris 10 compatibility
by tricking libbacktrace's autoconf tests.
The sysroot download routine is slightly changed, too.

(cherry picked from commit b3ea6e5)

(cherry picked from commit 0597bda)

[beta] Make Solaris builder compatible with Solaris 10 retry

Backport of #45343.

Connects to #45552.

Update the book on beta to fix the print button

Connects to #45552.

This does bring in changes to the text that we've made since beta branched, since we usually update the book just before beta goes to stable anyway, I didn't think this was a problem. If it is, I will happily make a branch of the book with just the print button fix and send in that instead!

r? @steveklabnik

* SDK tools is upgraded to 27.0.0.
   - Refactored to use `sdkmanager`/`avdmanager` instead of the deprecated
     `android` tool.

* The Java version used by Android SDK is downgraded to OpenJDK-8, in order
  to download the SDK through HTTPS.

* NDK is upgrade to r15c.
   - Dropped support for android-9 (2.3 / Gingerbread), the minimal
     supported version is now android-14 (4.0 / Ice Cream Sandwich).
   - Changed the default Android compiler from GCC to clang.
   - For details of change introduced by NDK r15, see
     https://github.com/android-ndk/ndk/wiki/Changelog-r15.