ANDROID: Move microdroid and crashdump defconfigs to common

They don't have device-specific modules. They are just generic configs
that are different from GKI.

Bug: 301852599
Test: run following commands
tools/bazel run //common:kernel_aarch64_microdroid_dist
tools/bazel run //common:kernel_x86_64_microdroid_dist
tools/bazel run //common:kernel_aarch64_microdroid_config -- menuconfig
tools/bazel run //common:kernel_x86_64_microdroid_config -- menuconfig
tools/bazel run //common:kernel_aarch64_crashdump_dist
tools/bazel run //common:kernel_x86_64_crashdump_dist
tools/bazel run //common:kernel_aarch64_crashdump_config -- menuconfig
tools/bazel run //common:kernel_x86_64_crashdump_config -- menuconfig

Change-Id: I8908a7499451ace0740979b694eb5fcc68398c61
Signed-off-by: Jiyong Park <jiyong@google.com>