SkDebug_android: undef LOG_TAG if defined
SkDebug_android: undef LOG_TAG if defined

In preparation for ag/Ib9bec1e1d72169a18e6ad1ce8f9008a65dbe5a71,
which will define it in SkUserConfigManual first.

Bug: b/224771432
Change-Id: I122895f089ce8949c028bccfcb971bd7d1c6ca72
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/521001
Reviewed-by: Greg Daniel <39df0a804564ccb6cf75f18db79653821f37c1c5@google.com>
Commit-Queue: Leon Scroggins <995cad867ca30d6399abe011583a53547c8afea1@google.com>
(cherry picked from commit 4a3601ed394392d2837a5055df8ef5907641a42b)
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/521358
Auto-Submit: Leon Scroggins <995cad867ca30d6399abe011583a53547c8afea1@google.com>
Commit-Queue: Greg Daniel <39df0a804564ccb6cf75f18db79653821f37c1c5@google.com>

aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia