Run some inputflinger_tests on host

Sometimes, it's convenient to execute the input tests without having a
connected device. This is especially useful when doing cherry-picks of
patch on a cloud device.

Allow input code to build for host, and enable the tests for running on
host.

Bug: 249591924
Test: atest --host --no-bazel-mode -c -m inputflinger_tests
Change-Id: Ib9be6a5fb6c35ffc450e41cb2a5688bfb2c8d01a
diff --git a/services/inputflinger/InputThread.cpp b/services/inputflinger/InputThread.cpp
index e2e64f9..e74f258 100644
--- a/services/inputflinger/InputThread.cpp
+++ b/services/inputflinger/InputThread.cpp
@@ -54,7 +54,13 @@
 }
 
 bool InputThread::isCallingThread() {
+#if defined(__ANDROID__)
     return gettid() == mThread->getTid();
+#else
+    // Assume that the caller is doing everything correctly,
+    // since thread information is not available on host
+    return false;
+#endif
 }
 
 } // namespace android
\ No newline at end of file