EGL BlobCache: Trim immediately on multifile overflow

While adding a fuzzer for this feature, discovered that
cache trimming wasn't happening right when the overflow
happened, but on the next iteration.

This CL updates the code to make it trim right away, since
we've already determined it needs to happen.

Also add a test to ensure trimming happens right away.

Test: /data/nativetest64/EGL_test/EGL_test
Bug: b/266725576
Change-Id: Ica1e9ca688268e7e746750c27acdfced04e74b06
diff --git a/opengl/libs/EGL/MultifileBlobCache.h b/opengl/libs/EGL/MultifileBlobCache.h
index b461ef4..f266011 100644
--- a/opengl/libs/EGL/MultifileBlobCache.h
+++ b/opengl/libs/EGL/MultifileBlobCache.h
@@ -119,7 +119,7 @@
     bool addToHotCache(uint32_t entryHash, int fd, uint8_t* entryBufer, size_t entrySize);
     bool removeFromHotCache(uint32_t entryHash);
 
-    void trimCache(size_t cacheByteLimit);
+    void trimCache();
     bool applyLRU(size_t cacheLimit);
 
     bool mInitialized;