Fix get_device_api_level_inlines.h in versioner

This commit fixes an inline and non-inline mismatch error caused by
`get_device_api_level_inlines.h`.

Versioner includes both `android/api-level.h` and
`bits/get_device_api_level_inlines.h` in the test.  When __ANDROID_API__
is greater than or equal to __ANDROID_API_Q__, `android/api-level.h`
declares a non-inline `android_get_device_api_level()`.  On the
contrary, `bits/get_device_api_level_inlines.h` defines a static inline
`android_get_device_api_level()` function.  These conflicting
declarations result in compilation error.

This commit fixes the problem by guarding full
`get_device_api_level_inline.h` with
`#if defined(__BIONIC_GET_DEVICE_API_LEVEL_INLINE)` so that
`get_device_api_level_inline.h` can be no-op when it is not properly
included.

Note: This is not revealed until recently because API level 29 is added
in Mar 14 and the prebuilt binary for versioner hasn't been updated.

Test: ./bionic/tools/versioner/run_tests.py
Change-Id: Ia7d5fbdcaf3d98787e60780f6cff2a24016324f5
diff --git a/libc/include/bits/get_device_api_level_inlines.h b/libc/include/bits/get_device_api_level_inlines.h
index 9c6e243..d14eb2c 100644
--- a/libc/include/bits/get_device_api_level_inlines.h
+++ b/libc/include/bits/get_device_api_level_inlines.h
@@ -28,11 +28,9 @@
 
 #pragma once
 
-#include <sys/cdefs.h>
+#if defined(__BIONIC_GET_DEVICE_API_LEVEL_INLINE)
 
-#if !defined(__BIONIC_GET_DEVICE_API_LEVEL_INLINE)
-#define __BIONIC_GET_DEVICE_API_LEVEL_INLINE static inline /* for versioner */
-#endif
+#include <sys/cdefs.h>
 
 __BEGIN_DECLS
 
@@ -48,3 +46,5 @@
 }
 
 __END_DECLS
+
+#endif  // __BIONIC_GET_DEVICE_API_LEVEL_INLINE