[Java.Interop] net6.0 is Version=v0.1.0.0

[jonpryor]

Context: cbd9666
Context: http://aka.ms/maui-schedule
Context: dotnet/android-tools@f0b3abd

The hope with commit cbd9666 was that we could "fix" an oversight
in our ".NET 6 Story": Java.Interop.dll should have a version
which matches the .NET SDK version, or at least doesn't match the
"Classic" Xamarin.Android version, to better support future expected
API changes to Java.Interop.dll.

Unfortunately, this change didn't make it before .NET 6 went stable
in 2021-November, meaning the net6.0-android and
net6.0-android31.0 target frameworks are "set in stone" to target
API-31.

My hope had been that we could implicitly "pull a mulligan",
fix the Java.Interop.dll assembly version in cbd9666, and make
net6.0-android32.0 (API-32) the default for MAUI.

Unfortunately, as per dotnet/android-tools@f0b3abdb:

We do not yet have all of our proverbial ducks in a row to bump
these Android SDK versions.

That remains the case: lots of moving parts means we won't be able to
make API-32 the default API level when MAUI ships.

This in turn means we have an ABI break: net6.0-android31.0 (the
default!) will want Java.Interop.dll v0.1.0.0, but current
.NET 6 Preview 13/14 is providing Java.Interop.dll v6.0.0.0.
This can only result in pain and suffering.

"Partially revert" cbd9666, and set $(JINetCoreLibVersion)=0.1.0.0.
This will cause Java.Interop.dll to be version 0.1.0.0, restoring
compatibility with net6.0-android31.0, removing pain & suffering.

TODO: when we start targeting .NET 7.0, we should revert this
commit, so that $(JINetCoreLibVersion) is once again

<_NetCoreLibVersion>$(GitBaseVersionMajor).$(GitBaseVersionMinor).0.0</_NetCoreLibVersion>

i.e. 7.0.0.0, as GitInfo.txt will likewise be updated.