Remove an assertion about lambdas not being public

A recent change in d8/r8 means that lambdas can now be public.
There are circumstances in which it would be safe for lambda
classes to be shared across classes (and
if they were known to be loaded by the same classloader)
and the JLS is silent on the accessibility of lambdas so
it is reasonable to drop the assertion from the test.

Bug: 73255857
Test: run cts -m CtsLibcoreTestCases -t libcore.java.lang.LambdaImplementationTest
Change-Id: I332bcf302de5acf1142c6bf065f40dd05cc11b64
1 file changed