Use -Werror in external/tinycompress

* Suppress non-critical warnings.

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Id0a4f4431f8420dbbe20ec541aa3be6a77567b7c
diff --git a/Android.bp b/Android.bp
index c22852c..f0000f1 100644
--- a/Android.bp
+++ b/Android.bp
@@ -2,7 +2,12 @@
     name: "libtinycompress",
     vendor: true,
 
-    cflags: ["-Wno-macro-redefined"],
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wno-macro-redefined",
+        "-Wno-unused-function",
+    ],
     export_include_dirs: ["include"],
     srcs: [
         "compress.c",
@@ -21,7 +26,11 @@
     name: "cplay",
     vendor: true,
 
-    cflags: ["-Wno-macro-redefined"],
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wno-macro-redefined"
+    ],
     local_include_dirs: ["include"],
     srcs: ["cplay.c"],
     shared_libs: [